Healing challenges not tracking (anymore)

Hi,

I've been having troubles with the healing challenges. Right now, the main Medic class challenge (Heal 5000) is stucked at 4258. It's been like that for three days now. And before that, it got stucked at around 1000s or 2000s. It's been a week, and I haven't been able to even get the medic badge (though it's my main class, the one I play the most). It is very frustrating, because I feel my effort is not having any impact on my own game...

Of course, it also applies to other challenges. Like this week's challenges, for example, I have to heal 2000 points and I've got 0 so far. 

I have tried different modes (mainly Breakthrough, Conquest, Rush, and TCTs, no Portal ever, though now I read it makes no difference). I have tried to make it count not just with the Supply Bag, though mainly with it, but by reanimating someone with full health too, as well as with the Specialization perk (the one where you resupply and heal people nearby for 10 secs...). 

I play on Xbox. I have cross-playing activated (would that be the problem? With cross progression?) I play daily. I am level 33 so yes, it's been a while since I unlocked the class challenges, and yet it's stucked in a random number. Please, help people like me enjoy the game again. It feels a bit pointless to play sometimes if no matter what I do I can't get nor show my own progress.

Thank you in advance.