Same seed from Electrum but generate different Bitcoin addresses
The problem is properly that you have a different account number because you said that you are using addresses starts with 1 (standard) so Purpose path is 44 and it's Bitcoins so coin path is correct (0)

You have to check that you are using the same account index while you importing the seed.

On your seed path try to increase account number by one and import your seed until you get your coins.

m/44'/0'/0'/0
m/44'/0'/1'/0