Aukey EP-T21 left earphone does not charge and connect

Hi, I received headphones in September 2020 but the left headphones do not want to work since morning.
When I charge it, it glows red for half a second and then nothing.
I tried everything, put them back on, take them out and put them back on but it doesn’t work.
But this problem does not occur on the right earpiece so only one of them works.

Please help me.

Pmease let me know if you can fix it, because I have the same exact problem. First, I thought was the case. I tried with another case from other EP-T21, and is the same issue, blinks red for 1 sec and does not charge. I tried factory reset, and still not working. It seems that the earbud is ot charging.