A month or so ago I got a new machine. I'm running Ubuntu 18.04 on it.
Everything worked perfectly until yesterday, when I started having intermittent connectivity issues from the wifi card (Realtek RTL8192CE). The connection seems to drop for seconds-minutes at a time, during which the card is still associated with the router, but I can't ping 22.214.171.124 or even the router. I know the router is up because I can access its web interface (and otherwise access the internet) from other devices.
Since I didn't touch the config or update Ubuntu at all, I suspect this is a hardware issue (although the effect seems to be less noticeable, if at all, when I dual-boot to Windows). However, I want to have a better diagnosis before I contact the seller for a replacement.
Any ideas how to diagnose this? In particular, how to figure out whether it's a hardware issue or a software issue?