Armor Non-Proficiency penalties are being applied to proficient characters 5e D&D

[Polarbard]

In my new 5e D&D campaign, I have a heavy fighter that is getting penalties for Non-Proficiency with Chain Mail armor. He has "Armor: Heavy", light, medium and shields in his Proficiencies.

I have added and removed his heavy proficiency, but He gets disadvantage constantly with the following message:

[SKILL] Athletics
[PROF]
ARMOR NON-PROFICIENCY
[DIS] [DROPPED (9) SECOND]

Please see uploaded images.

How do I fix this?

[Moon Wizard]

If you click on the gear button next to the AC window, you can toggle whether PC is proficient with the armor they are wearing. This is not changed automatically; and the sheet assumes that you are proficient by default, so it must have gotten toggled off accidentally at some point.

Regards,
JPG

[Polarbard]

Thanks!!

That fixed my issue!