Issue maybe not the same. When I check the database on my test site, i.e., laptop, I see the prefix wp_ (+table_name) for your tables. I use the prefix bu_ (+table_name), where the bu_ represents the name of the site. When I try to add a profile on the server at magma.ca where the bu_ prefix is used, your plugin says the profile has been created, but it is not listed on the profiles page nor is it found in the database. One solution would be to completely revise my site to use the wp_ prefix, but I think it would be better if your plugin allowed for site designers to choose their prefixes.