Help, After importing my private key and the address I get is different than what I expected! - OmniLayer/omniwallet GitHub Wiki

We sometimes get reports of users exporting a non multisig addresses private key from one of their other wallets and after importing it into Omniwallet the address that was imported is not the address they expected/wanted. While all addresses have only 1 private key, this private key can be used to generate a compressed and uncompressed address (which are different. Depending on the version exported by other wallets it can sometimes result in confusion. Take a look at this article for more information and how to convert between the two:

Converting between Compressed and Uncompressed Addresses and Private Keys