Switching user role on certain condition

Im using a directory theme called Listify. By default users get assigned the “customer” role after signing up free. When they Add a listing / Business and it’s approved by me (admin) with the order (woocommerce, me) they get converted to the role “Employer”.

Im running multisite and I think this is stopping this from happening, as it’s not working. So how can I enable this? Is there code for this condition and where can I put it?

It’s quite urgent. Thank you very much for your help.