How can I change the DTIM- and the beacon interval?It sounds like your battery may be draining or there is some sort of interference with the communication on Nest.
The best way to resolve this is to adjust 2 settings in your router. This will completely resolve your issue. Change your DTIM interval to 3 and your beacon interval to 211. Once you have done this, reset your Nest and this issue should not arise again.
I have a 2011UAS-2HnD Routerboard running RouterOS version 6.6.