so an update, I tried restoring using the seed words on electrum, this took a minute, but when it was done, it shows a balance $300 less than my current mycelium shows, in total its something like $500 less including that $200 from before.
That's not unexpected. Mycelium allows you to use/manage all three of the common address
types in the one wallet... so you can see/use "1"-type (P2PKH), "3"-type (P2SH-Segwit) and "bc1"-type (P2WPKH, "native segwit") addresses and their balances
all at the same time.
Unfortunately, Electrum only allows
one address type per wallet. The transaction you sent for the ~$150, sent the change to a "3"-type address. So, Electrum would not be able to see/display that address with it's coins.
If you restore your seed words on Electrum, but this time, select the "P2SH-SegWit (p2wpkh-p2sh)" option, you should then see the transactions/amount that is missing from the "Legacy (p2pkh)" Electrum wallet that you would have already restored:
NOTE: It might also be worth, creating a 3rd wallet, using your Mycelium seed words and selecting the "Native Segwit (p2wpkh)" option, and see if that also shows any transaction history.