Character Movement Max Acceleration stopped working

Hey guys, a bit silly situation here.

For the last couple of months I’ve been fiddling around with my first game starting from the Third Person Template and at some point I’ve lost the ability to change the movement speed gradually.
It’s instant full speed now and instant stop. I’ve checked all i could think of but no cigar. Changing values like Max Acceleration does nothing.

Any ideas where to look for the culprit? Help very much appreciated.

Thanks for your time

Ok it must have been a 4.21.0 bug because I’ve just updated to 4.21.1 and everything is working fine. Maybe that will help others with the same issue. Cheers