I should have taken around 0.0200 BTC, but when I check my electrum it looks like I got 0.0215 mBTC from that transaction
That means whoever should have sent you the funds, didn't send you enough. I assume bc1qsuyn3l59ltzg6rkdskr8xaqfhhlhwsrxumzfdj is your address, and the other two addresses aren't yours.
All you can do now, is contact the person who should have paid you.
why does it say that the estimated tx value is 0.02 on blocktrail but however, i can't see the exact amount on my electrum wallet then? isn't it really weird?
what about these two addresses you mentioned btw? you mean the money is sent to some other persons by mistake/on purpose?