Hi. I installed Lubuntu 20.04 soon after it was released, and have been reading this and other forums since then. You are not the only one who has had this issue.
My experience is that I had a lot of dropped Wi-Fi issues soon after the first system upgrade was installed. However, over time, it has gotten better. I don’t have an explanation for that, it’s just an observation. After a day or so, the dropped Wi-Fi stopped happening frequently.
Now, it happens about once every 2 days, and when it does happen, I have to re-boot. I haven’t found another way to successfully deal with this yet.
It’s definitely not optimal as I am working online from home right now, including Zoom meetings, etc. Haven’t had dropped Wi-Fi in the middle of one of those yet, but…
Previously, I used Lubuntu 17.10 on the same hardware, and I didn’t have any Wi-Fi issues at that time. I have no idea what is different in 20.04.
Sorry that doesn’t solve your problem, but I suggest keep installing the upgrades and wait a day or two and see if things get better.