TWS earbuds not longer connetable

For a few days now, only the left speaker has been working. I then carried out a reset (long press on the button on the container). Now I can no longer find them for pairing in the Bluetooth settings of various devices. Also the power on message when starting is no longer audible. But the LEDs light up. Any ideas about this issue?

Do you have a second TWS available to combine them in different ways to check them?

Is there an angel with a second TWS near you?

No there is no second pair