[tsac]

Ok back to the WIFI issues.
Reading I have seen posts in various sites indicating two different issues One is unless a user logs into Google there is limited access to many apps on a newer android cell phone. the Key2 is in that group. Apparently Google is trying to access virtually everything a user is doing. You may need a google login account.
The other issue is the selection of options. Users have had to shut off cell network and select only wifi use for call even is they do not have a carrier. You might try this.

The KEy1 had lte 4g issues. Users switched to 2.4 HZ to fix wifi issues. No idea who this fixes it but it may be a software bug relating to the radio.

The WhatsApp is just one of the new apps that want full control or they wont work.