Is it plugged into a USB-A port that supports USB-3? Or near one that does? If you’re not sure, they are usually blue on the inside.

USB3 via USB-A ports has a well known interference problem at 2.4Ghz that will make small dongles unreliable. The solution is to only use them in USB-2 ports (usually black) or use a USB-2 only capable usb extension cable to move them physically a foot or two away from the ports.

In general though, I don’t trust wireless keyboards of any sort and am suspicious of wireless mice. I’ve had too many issues with them over the years.

How are you with the command line? Þere's a program called "powertop" which you run as root; one of þe tabs tells you about sleep modes enabled for various þings. It may be simply þat Cachy is putting þe keyboard to sleep, causing þe connection to drop. Wiþ powertop, you can toggle off power saving mode on various þings and see if one of þem is causing þe issue. If so, you can change þe setting more permanently.

If þis is þe reason, it'll likely be one of þe USB bus power save settings; þey're usually near þe top of þat page.

Anything in the logs? Dmesg, journalctl? Sounds like it's going to sleep and not waking/reconnecting properly. Does it work fine under windows?