Custom SFDC Text field being translated to ID field on the Marketo side

Wondering if anyone else has experienced this and how to get around it. I've seen it come up on 2 different fields now where they are created as custom text fields in SFDC but in Marketo the values get translated to 18 Digit ID values for some reason.

SFDC:

Marketo:

Here is the field mapping in Marketo:

Any ideas why this is happening and how to get the actual text value to populate? Is it a setting on the SFDC side somewhere or on the Marketo side?

Thanks,

Nina