wifi calling keeps dropping calls

[#1]

I have Plusnet fibre broadband & a Plusnet router. The problem i'm having is when I use WiFi calling (which I need to because of signal at home), initially the call is fine and I can hear the caller clearly but after a few minutes or sometimes longer the call just goes completely silent without warning & I'm not able to hear the caller so have to hang up. When I call the person back usually my call attempt won't connect / ring for at least a few minutes, resulting in multiple attempts, and when I finally get back through the same thing will happen again. This happens 90% of the time so is really frustrating. If I turn my wifi off on my phone, and go to a spot in the house where I have mobile signal, this doesn't happen.

I have a Samsung S10 mobile on Three network. I also had the same issue with my previous Samsung S8 on EE network, I thought it was the phone or network but since I've upgraded & changed mobile networks & played with turning off WiFi calling at times, I've realised its my wifi calling with Plusnet. Does anyone else have this issue or know what it could be? Thanks, Sara.

[#2]

D/load a free wifi analyser programme, and then check usage of channels in your vicinity,
on each band. Your phone may just use the 2.4ghz frequency, so that's one to focus on if so.
Once you've seen which wifi channels are most in use around you, change the router channel manually to
the least used. Ensure the routers 2 frequencies are given separate SSID's too, assuming router
is dual band eg a PN Hub One. Or why not phone using your landline!

[#3]

Thanks for your reply. I've managed to change the channel to the least used for both the 2.4 & 5ghz frequencies as it looks like my phone uses the 5ghz so hopefully that will help.

I have unlimited calls in wiyh my mobile contract but I have to pay for any calls made on my landline (apart from free numbers) so I never use it as not affordable. Thanks again!