Thunderbird mail link doesn't launch in Chromium

I just installed the Manjaro 5.20.3 on a new hard drive about a week ago, and my default mail is Thunderbird. We have a database with customer information, name, address, email and etc. I usually use Chromium for the database. The email doesn’t launch automatically when you click on an email link in Chromium. How ever, the email launches on my second hard drive in both Firefox and Chromium without any problem. I only have run into this problem on this new installation, because I use Manjaro on several computers at work and home, and never had an issue launching an email by clinking the link in our database! Has any one run into this same issue?

Kernel: 4.19.160-1-MANJARO x86_64 bits: 64 compiler: gcc v: 10.2.0
Desktop: KDE Plasma 5.20.3 Distro: Manjaro Linux
Type: Desktop Mobo: Gigabyte model: B85M-DS3H-A v: x.x
serial: BIOS: American Megatrends v: F2 date: 08/10/2015
Info: Quad Core model: Intel Core i7-4790K bits: 64 type: MT MCP
arch: Haswell rev: 3 L2 cache: 8192 KiB

This is where you change the default settings.
System Settings>Applications> Default Applications

That is already set on Thunderbird. That’s not the issue. The funny thing is the email link launches in the same computer on my first hard drive with the exact programs and settings without any problem. So does on my other 4 machines. It only does this on the new Manjaro installation that I did last week. I even copy and paste and replaced the “.thunderbid” folder and Chromium in the “.config” folder from my first hard drive and still getting the same result. Thunderbird email doesn’t launch when you click on an email link in Chromium on our database. That is really wired to say the least!

Sorry but what OS is installed on those hard drives, also Manjaro KDE?
You may check also File Associations for everything “mail” related if set correctly, in spot #1 etc.

example xdg-mime query default x-scheme-handler/mailto

All machines Manjaro KDE 5.20.3 with kernel 5.4.80 (LTS) with identical programs.
I’m not sure what file associations related to mail. When I enter “mail” in search under the file associations, I see application, message, mulipart, and text. I don’t know what to look for after that. I’m also not following your example. Could you clarify a little more on that?
Do you know what files are associated with mail or email, or what files to look for so I can compare it to my first hard driver that is working?

Try reinstalling Thunderbird…

Already done that, no difference.

The command in the example show which email client is set for email handling when clicking on a mailto link.