@mstrauss has a good solution.
Yes, is pathetically easy to jam up the two sides when moving them by hand.
In fact it is to be expected.
This is the one I chose to do.
It has been 100% trouble free and still hasn't lost any belt tension after many dozens of prints (I have lost count).
The 1350mm long belt is just barely stretchy enough that it stays tight like a rubber band.
An alternate version I considered, but I wanted to keep the center area wide open for the bed heater wires-
Please note that there are many, many ways to resolve this problem.
@mstrauss has a good version, @Walter has a good version, you might like mine, and there are dual belt versions, some of which have been posted on thingiverse and of course on this forum.
The point is- linking the two motors together or going with a single motor will solve the problem. Take your pick.
Any two-independent-motor solution is only a band-aid IMHO.