That sounds interesting. Would it tell anything about the derivation path or other wallet properties? How does the script used to send help in my case?
It wouldn't tell you anything about the derivation path, but it would tell you if you are indeed looking for a standard nested segwit address. If you are, then we can tackle finding out the derivation path. If the script is something different, then checking derivation paths as you are doing with Electrum or similar will get you nowhere.
Can you guide me through the steps without me exposing my pub keys?
Find one of your addresses from the mSIGMA wallet which has sent coins out from it, and grab the TXID. Head over to
https://mempool.space/ and look up that transaction. Click on where it says "Details" on the right hand side. Underneath your address the first field should be titled "ScriptSig (ASM)". Hopefully next to that it says "OP_PUSHBYTES_22", followed by "0014" and then 40 random characters. If it does, then you've got a nested segwit address. If not, then you've got something different.