Soundcore Liberty Air not turning on

[ddddmp]

Hi,
I bought a pair of Liberty Air earphones several months ago but never used them.
I let them charge all night long and now the 3 leds on the case are turned on.
On the earphones, however, no LEDs light up, neither when they are inside the case, nor when I take them out of the case.
I cannot pair them with the phone because they do not appear in the list of Bluetooth devices.
I also tried the reset procedure but they do not show any signs of life.
What can I do?

[Tank]

Make sure that the plastic covers for the charging pins did not get dislodged inside the case blocking connection

[ddddmp]

Thanks for the reply.
No plastic cover is present on the charging pins