No new devices can be found by Alexa

[jeshab (Jeremy)]

What happens if you restart your device? Degraded performance on a Raspberry Pi is not only tied to Zram. Try to disable some of your addons if necessary.

Alexa skill stops working

If the performance of your Raspberry Pi is degraded, it will affect your Alexa experience with OH. The fact that after you restart your device, it is working again would point to that root cause.