Help. Rear light and stop light don't work LHS

[grabedy]

Hi. I'm confronted by a strange situation. I'm getting error lights on the left rear stop and position. I'm afraid that the defect appears and disappears. I checked the bulbs, the fuses, the wires, all are ok
On the left side I have this defect. It suddenly comes back on its own, but it is annoying.
advice, please.
Thanks.

[CDTI Dave]

Using normal bulbs? Or LED ones?

[grabedy]

Normal bulb