Why does my inverter keep going off-line?

I've had my system (3.2KW panels, Solis inverter and ac3.0 +8.2 kw battery) since June. Everything was fine until a month ago when it suddenly went off-line for a couple of hours, and then spontaneously came back on its own. But in the last week or so it has started doing it more often - about 3 times yesterday and twice just now ( just as I wanted to sell leccy to the grid!). Can any one give me a clue what is causing this,? Today it was off for about 20 mins each time and came back on its own. The blue dongle was flashing. I tried restarting the inverter on the portal but it didn't want to know. Last time someone suggested re booting my router - how do I do this and will it mess up the connection to my smart TV (that by the way is the only thing that has changed in the last week - new TV - could that be having an effect? ) I have also been alternating between the app and the portal to change settings and I wonder if I have confused it somehow by having different settings in each of them? As you can tell complete techie numpty!!

Karen How good is your WiFi signal? Some routers seem to not play nicely with both 2.4Ghz and 5Ghz SSID's with the dongle. Also don't play that nice with range extenders either. The dongle will only connect to the 2.4Ghz SSID - if you have access to the router you could try turning off the 5GHz SSID and see if that helps

OK - total idiot here! how do i know if i have a 2.4 or 5 Ghz SSID? And - how do I turn it off - and - will this mess up the wifi connection to the smart tv?

OK - Google is a wonderful thing! I found a post on how to ID your SSID using an android phone - apparently it is 2.4Ghz. The inverter is also listed on my Wifi networks - but the signal isn't as strong as for my plusnet broadband . The signal strength is about 1 as opposed to 4 for Plusnet. Is this the problem? Is there anything I can do to make it better? I thought about one of the signal booster things (range extender?) but you imply this doesn't help either.

Karen I’m not saying it doesn’t help - but others seem to have had issues.

Well worth trying though as a signal strength of 1 is probably marginal.

Karen I have a TP-Link range extender via the mains for my inverter in the garage. This works well but every now and again, I have to reboot the TP-Link. I don't know why...
Reboot= switch off master TP-link in study near router, switch off TP-link in garage, switch on master (after running upstairs again) then switch on TP-link in garage. That usually seems to sort it. I use the AV600 Powerline, about £30?

Trying something a bit more basic first. I noticed that the lights on my router went crazy when the new TV is on - it's connected to the Wifi. So I've tried connecting it with an ethernet cable instead to see if it will relieve some of the pressure on the Wifi so the inverter signals can get through. Not technical so I don't know if it will make any difference - but no issues today so far.

Karen Wired ethernet to your Tv would always be the better option - though if it does turn out to sort your issue out, it suggests your router wifi is getting saturated and can't deal with the through put. Unless you have a lot of wifi devices it shouldn't happen - but its not unheard of and why many people have separate wifi access points.

The other thing to think about is WiFi channels. Most routers just use a couple of channels, and if everyone is on those channels it can cause an issue. Using an app to scan wifi channels, finding which one has the lowest number of other SSIDs on it and using that could help improve your connection.

Cdent I’ve not found an app on the Apple Store - but there are some on android that work well. Wifianalyzer is what I use