Master key matches the key I have on the providers website. but where it says "Next 5 addreses generated by your public key"
None of those addresses match my wallet.
In which case... it's most likely that the provider is not using the same derivation path as Electrum...
For instance... from this xpub from Electrum:
xpub661MyMwAqRbcFFuDRX7BMSzUcPukXGRQE7Wqmy2YiekQS56meYFDke48usmCpiYo6ZGkNjRQKnMSMnXrsPaezthU3uyWwj27CxxTs8NYgqF
Electrum uses the derivation path: m/0/x to generate the addresses... so the first address I see in Electrum is: 1JmZPy7YG4TRMovrSpN4RLAGcGYuhcAbso
You can confirm on:
https://iancoleman.io/bip39/ Put the xpub into the "BIP32 Root Key"... click BIP32 Tab... set "client" to Custom, set BIP32 derivation path to: m/0
You will then see the address at the bottom:
Does the service provider give any hints on what the derivation path they are using for xpub's is?
If not, you might need to experiment with your xpub and the iancoleman BIP39 tool above to figure it out.
Are you able to advise which provider you're using?