I think he's a troll but the fact that he was able to get OP's telegram handle bothers me. I hate how some users are so obsessed with merit and how far they are willing to go to get it. It says the phone number is from Bangladesh, and since this person was pestering you to check your thread, it casts suspicion on everyone who has posted on that thread recently and are yet to get any merits.
Even if I could match a user from Bangladesh who posted on my merit thread and possibly on the translation one, maybe involved in some scam project in the past, I couldn't point him out with enough degree of certainty to be able to send a red trust.
The person in question is very smart and was not even stupid enough to include anything in his or her telegram username that could link to the forum ID, and that way, the approach Fillippone could take could put everyone who posted on his translation thread on a suspect list, but since you have not pointed him out, maybe he will definitely make a mistake anytime soon, which could single him out, or he could probably keep playing smart, but mistakes happen; we never can tell.
Atleast the approach of changing your handle name would reduce this sort of situation and also maybe change the privacy settings too.
He has already done that – disabled calls from unknown contacts – which was what he forgot to do, which this intruder maybe reminded
him to do.