@David-TP, yes -all my mobile devices have same issue. There are two laptops which - if working in one place - have acceptable connection. All other devices (more than 5) have same issue. I solved...

I have a 3-pack of Deco x20. Main Deco working as wireless router and the two other units are both wired to it using a TP-Link Gigabyte switch. My mobile constantly looses internet connection (still...