Has anyone else experienced an issue with verbal warnings being “clipped”?

My setup is iPad mini and Bose A20 connected via Bluetooth. Everything works perfectly initially but after a period of time (maybe 10 mins I don’t know) the warnings become “clipped” and often don’t come through, almost like something is in some sort of “sleep mode” and doesn’t wake up fast enough?
Sorry to be so vague!!

I eventually tracked this down to an iPad issue; when the processor is running towards capacity the Bluetooth connection suffers.