So, i’ve same problem. I installed trust wallet in April 2018, and made the first ether wallet. It had 2 nets, callisto and ether. Then, in December 2018, I added another already multi-currency wallet and saved 2 phrases. Recently I changed my phone - from 2 wallets the phrase is suitable, from 1 wallet no. Maybe the old version of the trust is needed?
there was also a file like “trust_backup_WALLETNUMBER” how can i restore wallet with that file?
Nope. It will still use the same derivation path. Try to follow this guide and check for your addresses and its corresponding private keys (even though you didn’t send it to an incorrect address): How To Recover Funds Sent to a Wrong Public Address
Might as well follow this guide too (except step 6): My Crypto is Missing, What Should I Do?