Ubuntu is based on Debian, but it differs in quite a lot of ways.
Probably, they didn’t use dkms to install their custom wifi driver. If that was the case, Debian and Ubuntu behave identically and the driver isn’t added if a newer updated kernel is installed.
Especially if you use Ubuntu’s 6-monthly releases.
If their driver was included in a user PPA, it’s gone after a Ubuntu release upgrade and the sources.list of the PPA is deleted.
Well there’s your problem. Ubuntu is based on Debian, but it differs in quite a lot of ways. Especially if you use Ubuntu’s 6-monthly releases.
Probably, they didn’t use dkms to install their custom wifi driver. If that was the case, Debian and Ubuntu behave identically and the driver isn’t added if a newer updated kernel is installed.
If their driver was included in a user PPA, it’s gone after a Ubuntu release upgrade and the sources.list of the PPA is deleted.
IME PPA-sources.lists get disabled, not deleted.