I would not give up. We have some thousand GHL Dosers out there, the huge majority is able to use the WiFi.
Maybe it makes more sense to seek for help at the official web page rather than in this is thread. https://www.aquariumcomputer.com/support/
There are a lot of helpful resources. If you can't find the right information either go to the dedicated GHL support forum or open a ticket.
In case you already opened a ticket and your problem could not be solved there yet please don't hesitate to remind the support staff you still need help.