Firstly I want to thank you very much for letting me cross the 50$ mark! I never thought that would happen so thank you!!
Secondly (again): I am currently in Brighton until the 3rd of May so don't expect anything until then.
Thirdly, I haven't posted an update for what I was doing on the 19th but I was working basically my whole day again on getting WiFi to work, but unfortunately I didn't succeed then... I got a bit of help on the #lineageos-dev channel (on freenode) but they don't really seem to know the exact problem either (basically told me I should get "qmi" to work (which I did) and I didn't ask again afterwards because it was too late already).
Thanks for your support!