What should I do if the “SIM card not found” error periodically pops up on the iPhone when it is in the tray?

Question

iPhone

Periodically an error pops up, they say the SIM card is not inserted. There is no definite pattern. The physical position of the phone is not affected, as is the impact (specially shaking it). Time - no, battery charge - no, the presence of a plugged charge - no. Sometimes it even crashes during a conversation. Accordingly, it is not possible to get through.
Treatment - pull out the tray and insert back. Any physical impact, such as tapping, shaking, does not solve the problem, just take it out - insert it. Previously, this was not observed, the bug appeared just about 3 days ago. The SIM itself sits tightly in the tray.
Simka works without failures on other phones.
Is it worth contacting the service? What can be the cause of such a "jamb"? What physical module? (tray or radio?)
Specs:
- iPhone 5 neverlock
- Vodafone 4g ready sim
- Tricky audio codec on the board

Answer 1

I would put another SIM card into the phone (temporarily), and check how it behaves, if OK - replace the native SIM card, if not - the phone is for repair.

Answer 2

Take it to a service center.

Answer 3

It could very well be a sim. I would change it first. It's like it's free.