LAN Controller version 1.2 SW:2.43

[wilkxt]

version 3.xx don't have watchdoog
version 2.xx have watchdog
you may use 3.xx or 2.xx on this HW.

OK. Thanks!
I will firstly try 'V2.59 (Filename: lc10_v2_59_HW1_2.bin (322.4 KB))

I updated to V2.59 but it behaves in the same way...
Do you think that  a problematic UTP cable may produce such a behavior? The controller is connected to the router with a cable of about 30 m. 
Does the browser interface need a better connection quality than the mail client?

Browser interface don't need hihg speed, it is about 80kB/s.
It is hard to say what could be the cause.
Maybe you will try a new version with more possibilities?  https://tinycontrol.pl/en/lan-controller-35/