I would agree with Tim, it looks like you have two records connected in that join. You can’t therefore place ALL the record values in that connection into a single field, that’s why you’re seeing “{object object}” etc in Tadabase it can’t complete the operation as it makes no sense as such. Do you want to get all the records (Richy Harry, Jayne Harris and any additional records) or do you only ever want the first record (Richy Harry). If you just want the first you should be able to specific that in MAKE by stipulating you want the first record in the array or collection or if you need them all as Tim says you need to step through each one with the iterator
https://www.make.com/en/help/tools/flow-control#iterator-935250