Generally repeater issues are related to incompatibility in what is called WDS. There is no actual standard so things from various vendors many times have issues connecting.
I really doubt the ssid on a 5g band will make any difference. Since the single band devices cannot even see the ssid on the 5g how could it affect anything. Now if both devices were dual band and you let them figure out how to connect using default settings they I would suspect they could easily get confused.
Generally you are best off manually configuring the options on the repeater ...if you can some are designed to only run with their auto "magic" configuration.