Electrum only supports 1 "Mycelium Account" per Electrum "wallet"... when you restore in Electrum, you just increment the "account" number value in the "derivation path" that is displayed on this screen:
try:
m/49'/0'/1'
m/49'/0'/2'
m/49'/0'/3'
m/49'/0'/4'
m/49'/0'/5'
m/49'/0'/6'
Note that you might also need to try the other address types (like "Legacy" and "Native Segwit")... if you've used different address types within your Mycelium accounts. Again, change the "account" number in the derivation path:
Legacy:
m/44'/0'/1'
m/44'/0'/2'
m/44'/0'/3'
m/44'/0'/4'
m/44'/0'/5'
m/44'/0'/6'
Native Segwit:
m/84'/0'/1'
m/84'/0'/2'
m/84'/0'/3'
m/84'/0'/4'
m/84'/0'/5'
m/84'/0'/6'