CAN listen to music CANNOT hear phone calls - EP-T21 - iphone XS

Greetings!

I have been using my Aukey EP-T21 earbuds my iphone XS since February 2020. They worked excellently and with recent updates have developed a glitch of some kind.
I can still listen to music, podcasts, and music in both earbuds or in a single, but in the last 4-6 weeks I can no longer hear phone calls through the earbuds. The buds are connected, they don’t drop the connection, they just don’t like “talking” to the iphone for phone calls.

Have you seen this before? Is there firmware or something in the earbuds that I need to update? Thanks for any potential solutions.