I found the reason why the prestige bar was broken in this mod (it is still working, we just can't see it). The modder set the levels too high. The vanilla level to trigger the RD was 100 and he set it to 1200. I think pass the 1000 the game don't recognize the value so it stops showing the progress bar. I suggest you try to put the limit to 999 and see if it works. As for me I put it to 200 and it's fine.

Cheers.

p.s. it's just a visual bug, the RD still work with the value put by the author of this mod.