Calls build up on the screen of Digium D50 phones

Sorry if this question has been asked before but I couldn’t find any posts that speak to this point. Basically we’re using Digium D50 phones with freePBX 12. What happens is throughout the day some phones will get a build up of calls on their screens as if they’re incoming calls. This confuses the techs because they thing they’re live calls when in fact they’ve already been answered by someone else. The only way to remove these calls is to ignore them on the phone. Is there some setting or patch or something I’m missing that reduces or prevents this issue?