The router in question was working for less then 6h and DHCP leases are set to expire in 12h.
During the most resent bug occurrence only one device was connected to the network. It's an older netbook working 24/7. It was there on the previous router so I don't think it's the culprit. It is a 100Mb/s device so it's affected by this bug: https://forum.openwrt.org/t/tp-link-wr1043nd-v4-issue/
Can the bug discussed in the thread linked above cause this issue?
I think this was a LEDE problem in general and it was fixed by adding a rule to firewall. I have this rule added in my configuration but the problem persist with or without it.
What do you mean? I didn't change the vlans. I have the default one untouched.
I can provide my configuration files here if this would help.