(v16, linux)
The ground coloring of reachable tiles will not redraw after using a perk.
Easy to test this is to use one of the 2AP costing perks at the end of a turn, and then it shows as if you can reach further than possible (see attachment for illustration).
I'm not 100% sure, but it also happens to me when using Adrenaline. Situation is opposite, as it's not updated I can then step at tiles outside of the reachable coloring. It will update if you change weapon or mode.