It’s not a bug, it’s a feature! 
KDE recently introduced “Remember Window Positions” as default, but they haven’t added the ability to disable it via GUI yet. That’s coming in Plasma 5.20, which is expected to be released later this month.
When Plasma 5.20 arrives, there will be a GUI checkbox for this option; it will be located at System Settings → Workspace → Window Management → “Advanced” tab. The checkbox will simply add the line that I posted above.
great feature indeed
After running the update (Manjaro Gnome), I updated grub and saw that my perviously installed kernels were gone/ not read, so I reinstalled them.
All fine now thanks @Manjaro-Team
I’m no longer able to copy files from my NAS to my internal drives. The message is: “Error when getting information for file descriptor. Numerical result out of range.” Some symbolic links to the NAS broke as well.
This appears to be https://gitlab.gnome.org/GNOME/glib/-/issues/2189, so it’s a GLib rather than a Manjaro issue. Posting this more as an FYI for the Manjaro team and anyone else who might have problems.
Smooth update with no issues on Gnome, kernel 5.8, nvidia 450 series driver.
Same for me witk Manjaro-KDE: Event Calendar breaks Plasmashell.
Before to do the update I make a Timeshift backup, so will be easy to restore the previous configuration, uninstall Event Calendar version 66, make the update and afterthat install Event Calendar version 69 and all works without any breaks.
Thanks to the forum for the above indications 
The update went “OK” as in I could reboot, login, fire up my browser, browse websites, write this comment, use docker and vscode (comes from the AUR though).
The “bluetooth-stack” leveraged a new config, which resulted in me having to merge my /etc/bluetooth/bluetooth.conf with /etc/bluetooth/bluetooth.conf.pacnew with a little effort. Still I believe this could be “smarter” by splitting the config up in separate files, like how NetworkManager is doing it.
Apart from that, I’m under the impression that the KDE devs do NOT use THEIR desktop widgets AT ALL.
After upgrading, the legend’s text of the Widgets disappear. And occasionally appear again at each login, but not every time.
Attempts to recreate the widgets as they were, did not work well. For example for the Disk Usage Widget, the values of my home-partition and /-partition got swapped 
It does not make sense how this/those regression(s) could slip through the quality control checks.
/rant
You have to keep in mind that the KDE team doesn’t write all the “widgets” aka Plasmoids. The responsibility of making sure the widgets work with the new releases is up to the widget developer. Part of running a rolling OS is you get all the latest goodies as they come out, the downside is that some parts of the OS move faster than others. Not every widget developer develops their widgets as a full time job, many are done in their free time as they have time to do spend on their “pet projects”. People seem to forget that a large part of the open source community is done by volunteers in their spare time at their own personal expense. The reason they do it varies for their own personal reasons but it is unrealistic to set your expectations that they are going to commit a 40 hour work week 365 days a year to develop free software for others for free, some of these people actually have lives where they have to pay rent, buy food, occasionally spend time with their families, etc…
The update was relatively successful on my Gnome laptop.
I had the same issue with gnome-terminal that was reported by others but the solution from @SweetestRug seems to have sorted it out for now.
Pamac is telling me it will replace util-linux-libs with libutil-linux due to a conflict. Is this okay?
Always agree. Always.
Haha. Earlier this year, I agreed to something in Pamac blindly and then I had to spend 2 days manually sorting packages with pacman because my system wouldn’t boot, and this was not due to pacnew files. So, instead, my policy is, “Never agree without asking. Never.” and that’s worked better.
It’s just a change in the name of the package:
No one said you should blindly do anything. If you’re not sure, disagree and watch the process fail. Then you know you must agree.
Nothing wrong with asking, either way. 
cannot upgrade
what should do i do
error: failed to commit transaction (conflicting files)
ruby-reline: /usr/share/licenses/ruby-reline/COPYING exists in filesystem
ruby-irb: /usr/bin/irb exists in filesystem
ruby-irb: /usr/share/licenses/ruby-irb/LICENSE.txt exists in filesystem
Errors occurred, no packages were upgraded.
problem solved after update via pamac
Don’t install ruby gems with root. Either use repo packages or set a GEM_HOME environment variable:
export GEM_HOME=$HOME/local/gems
$ gem install rhc
Is there some sort of merge tool that we are supposed to use for this. Up until about a month or so ago I hadn’t realised what this was and would just blindly overwrite the existing file with the *.pacnew. That was until I messed up my laptop. Now I run diff on the two files and either manually edit the old file with nano, then delete the *.pacnew file or manually edit the *.pacnew file and use mv to overwrite the old file with it; whichever is easier. This does feel a bit clunky though. I was wondering whether anyone has a better way?
As a noob I do not even want to imagine what monster 
the OS turns into if you say NO at those points.
In my eyes those moments are preset traps for us, noob Win users. You know our response: interrupt!
Hello,
I had the following issue:
make the uptade
restart
login in the session
then black screen and the cursor !
I tried “alt space” to launch something: it was possible to launch the applications.
Then I tried the solution on the above post:
If anyone else has the issue with plasmashell starting and stopping, check if they have the plasmoid “eventcalendar”. Deleting it fixed the problem for me.
.local/share/plasma/plasmoids/org.kde.plasma.eventcalendar
restart
and then, all was ok; thank you guys 
such a big issue with a small “event calendar” plasmoid;
again thank you all
Yes there is: