Slow downs in head unit and function

If its a JBL head unit you might try holding the power button for the head unit ON for a couple seconds which might elicit a restart. The power button on my car is marked Audio. That might be a standard procedure back to a 2017, don't know. We always have to ask about your 12 volt battery health whenever electrical shenanigans appear. The Gen IV auxiliary battery is more robust than the earlier generation motorcycle battery but still subject to aging. If it's OEM you might have it load tested to eliminate that possibility. An mpg drop might also be an indicator of 12V battery troubles as the system continuously tries to charge the battery by running the ICE more often.

 

Certainly worth having the 12 V battery tested.......but it would have to be in REALLY bad shape before excess charging time would have a noticeable impact on your fuel mileage.

A loose main cable connection might be a more likely culprit.