Units receiving replacemnents for lost hits

[Ebbingford]

Playing as France, FIW, 1.10e +QF2.
I noticed this playing as the Brits too, but is more noticable here.
Units don't seem to receive replacements for lost hits when in theory they should do. Not all the time anyway.....
Case in point. I have a stack at Fort Carillon, dug in, with a depot. There is more than enough supply for the stack. The stack is at 100% supply and the region is not pillaged. I am noticing that the units are getting weaker most turns when in theory they should be gaining strength each turn ready for the big push south. They don't always lose strength, but most. It looks like replacements aren't happening every turn, just occaisionally.......
On one turn the strength went from 534 to 521

[Durk]

I am never certain if issues like this are computer specific or something I have just never noticed. For me in the FIW if elements are below supply and are in a city or structure, the replacements flow. I have never seen a fully supplied force lose strength unless you are playing with historical attrition; and a your force is not moving even that setting should not matter.
I know, not what anyone would call help.

[Pocus]

Are they getting weaker by losing hits or only cohesion?
It might be because of the weather, I believe there are a variant in the rules where the weather is nastier and there is the possibility to be weakened by foul weather even if in supply and in a city.

[Ebbingford]

I think it is to do with wilderness and weather.....
Only seeing it around the Fort Carillon regions......