Stacked extractors giving incorrect xp

Our med kits stack to 15, so the skill extractors also stack to 15. When you use a filled extractor, it consumes the entire stack but doesn't give all of the xp it should. It worked for a stack of 2 that I tried, but it doesn't work for larger stacks. We don't use the empty ones currently but that might have the same issue.

We use Carbon and use the built-in stack manager, if that helps.

Thank you, that'd be great. We are using them right now as a reward for a lot of events. Should we disable it for now? Or do you know when it might be updated?