Fenix 5 Plus does not sees any Wifi networks

All attempts to solve it by configuration or software updates failed. Watch was eventually replaced by Garmin. 

Just got a Fenix 5 Plus and out of the box it wasn't finding any networks at all. However just updated firmware (to v13) on the watch and now all is working and the WIFI networks are being found

The Fenix 5 plus had severe Wifi issues when it was launched. The problems were solved with several updates over the years.
I could not connect with my Vodafone Cable router, but since last week even that works. As this was the only router, which did not work with the F5+ (and with my sons Venue), it was very likely an issue of the router and I assume that an update of the router solved it, as there was no update of the watch. 

In general the Garmin watches (and most other smartwatches) do not connect to 5GHz Wifi! Maybe this is helpful for those who still have issues.

Mine was working great until the update to 13 and now it won't connect. Sometimes it finds the networks but then crashes upon any attempt to login and requires a hard reset. Doesn't matter if the network is added via the watch or via the app.

That's strange. The only idea I could provide, is to remove the connections, do a soft reset (switch off and on again), connect to your computer and setup the connections in Garmin Express. Maybe that helps.

Recognizing this started 2 years ago with updates as recent as 6 months I offer this possible solution. My watch lost networks after a software upgrade. Various messages of "no networks"

Without all the details which I have posted in similar thread, the simple two step process for me were to:

Using the WATCH, delete the networks (specific steps covered in manual) (menu>settings>networks>yadah>yadah)

Using smart phone Connect app (not IQ) add the networks back (of course with passwords) :-)

Smartwatch,being dumb, searches again for the networks, finds them and connects

There can be issues if your wireless router was upgraded from 2Gs to 5Gs, this method above also solved that for me. Verizon went from 2.4 or 5 to 5G.

This has not been an issue of encryption WEP, WPA2 (AES or TICK) or WPA3. Advanced Encryption Standard (AES), older Temporal Key Integrity Protocol (TKIP) or first Wired Equivalent Privacy . Fenix 5 works fine on WPA2 and WPA3 in my case.

Not trying to turn this thread into an encryption thread, nor a router thread, just identifying possible "but what if I have XYZ?" These XYZ did not impact making my smartwatch dumb again, and forcing it to relearn the WiFi networks. It did it in short order :-)

I have fenix 6 X Pro and it is having same WIFI problem as yours in this thread. Any suggestions or solutions?

Can you please explain how to do it? I am facing WIFI issues on Garmin Fenix 6 X pro. MY WIFI version is 655.35 and it is not able to serch any WIFI connections from last one week.