some thoughts regarding WIFI:
what has been working in the past doesn't mean it is working today or in the future, cause 3 (!) components are involved: your device, your router and your neighborhood's router
if I can't evade my neighbours channels:
the best channel I use is the same as the strongest one of my neighbour, cause of lesser signal distortion.
IFAIK in this setup my and the strongest neighbours station are sending alternately with a ~full~ signal versus destroying the other one, even when channels overlap.
regarding AVM router:
on 2.4 GHz: the channel 13 is usually switched OFF per default, might mean rare people use it in your area...
=> channel overlapping ?!
on 5 GHz: channel 100 sends with 1000 mW (the whole 2.4 GHz band and all other channel <100 on 5GHz send with 200 mW only, ). but using channel 100 could cause hickup's cause of radar detection/scanning ...
auto channel is OFF, cause side stepping each others whole the time leads to never stopping side stepping.
using fixed channels leads to side stepping too, but not here on *my* router, even when I send with 1000 mW (somewhat hardcore though)
 at least for AVM Fritzbox 7490 and 7590
I do not have any trouble with wifi here with my GT-I9505.
but my wifi use case is only: fetching the updates from LOS server, syncing with thunderbird, installing downloded apps via samba (and MiX).