Well more info is needed.
So it seems you have had the phones a while and have had your same isp provider for a while. Have you had the router since you have had the phones?
What is your carrier? And do you and your wife have the same phone?
Are you on the latest Oreo OS?
Since you can get wifi on another router/etwork, this proves the phone is not the culprit, so this fourm may not be of much help. Sounds like your phone(s) is/are working normally yes? (Making calls, web browsing, etc).
Your next course of action is reaching out to your ISP. Asking if there have been any local issues with your internet.
Are you on cable modem? Comcast? Just guessing.
Next up is the router as was mentioned already. Did you make any changes on the LAN side recently? Maybe worth a factory reset.
One other thing you can do is clear your phones cache, which is done by having the phone in a power off state and turning it on via the bixby+power+vol up button until the android robot screen pops up and selecting the clear cache option. This procedure is easily found online if you want to understand more about it.
marctronixx,
Thanks for the reply. I will reply briefly in a broad sense right now and will tackle more of the questions later.
Our phones are working properly, and that is a relief, and probably preferable, as a cable modem and wifi router are cheaper than phones.
Nothing has changed, other than the following.
A) Both of our phones are about 6 weeks old. Mine is a Note 8, the wife has a Samsung Galaxy S9.
B) There were no hardware or software or ISP changes aside from the new Phones themselves (our prior phones were not wifi call capable), and that I put a new key on the 2.4 ghz channel. I changed the settings on our laptops to reflect the new key. I found out that the job was not that simple, as we had wifi printing issues after that. At the time, when rushing to go for vacation, the simplest solution was to go back to the old wifi router key both on the router and laptops and get wifi print capability back, which it did. None of this affected the phones, as both are on the 5 ghz channel, which was untouched.
The problem here is, as you touched on, it seems to be a network issue, which may be beyond the scope of this forum, but on the other hand, as it concerns the use of phones, it may also be beyond the scope of a computer forum. Unfortunately, this is a difficult thing, a multi-discipline issue.
Danny