I am having the same issue but with the SE-44C Milestone.
This is affecting all milestones now. Just getting worse
Same issue - PC. I was grinding for the TL-50 adds, got the first, but can't claim the reward. So... maybe the second reward will trigger an evaluation and unlock. Nope: Grind that out - painfully - and they are both locked out. Meanwhile, before getting conditions for the second TL-50 add finished, I unlocked and accessed rewards for other tasks successfully. My reward lockouts are only affecting the TL-50 (so far) and have now persisted for a few days and several restarts.
Having the same problem with one of the guns for heavy trooper and the achievement for getting 500 kills for multiplayer! Tried everything!
I have the same problem.
I even almost completed the next step of the weapons milestones but still haven't received my weapons mods.
