As far as I know that is an Operating System setting.
So unless you changed something there recently it should not have changed.
The problem with this is if you turn it on/off then it may be different if you open the same file on another machine.
Turning the comma off will not affect existing dimensions, so you will now get a mix.
At least this is what used to happen years ago when I looked at it.
Barry.
One of the forum moderators.
Versions 6.5 to 25
Dell XPS- i7-6700 @ 3.4Ghz, 16GB ram, GeForce GTX 960 (2GB), Windows 10
Dell Precision 3510 - i7 6820HQ @ 2.70GHz, 16GB RAM, AMD FirePro W5130M, Windows 10