Hi @_rusteh welcome to the /e/ forum.
Please could you clarify has this or another SIM been tested on this /e/ install ? Was a SIM installed when the First start wizard was run (where Region, Language, Time & date are set straight after /e/ is installed) ?
Your case reminds me of this
In the first instance I would check out the references in the above case to Access Point Names #apn ← is a hashtag to other threads on the subject.
- There are other cases revealed by this link to a search of the forum SIM not detected.