What’s weird is that it says version 4.11.0 is installed, even though I chose 4.10.0.
Caveat: megasync is now not in the list of programs within the Application Launcher anymore, so I needed to run megasync via commandline.
If they were using the AUR, but it is pointed out instead they are using the third party mega repository, with it already built, hence the file requirement that Stable Branch cannot meet.
This is exactly why third-party repos and/or the AUR should normally not be used while using the Manjaro stable branch. icu 74 is currently only available in the testing and unstable branches.
Using third-party repos and the AUR assumes you’re using Arch stable. The Manjaro unstable branch syncs with Arch stable several times a day.
Either way, neither are supported by Arch nor Manjaro. Please RTFM (Read the Friendly Manuals):