I sometimes lose web access to my CSS106-5G-1S switch (and everything else behind it) even though it is showing a link on the router it is plugged into. Disabling and enabling the port does not fix it, but power cycling fixes the issue temporarily.

I have the SwOS watchdog feature enabled, but it is based on a generic CPU fault detection within the switch itself and so it cannot detect L2 problems as RouterOS's ping-based watchdog can. I am going to try turning this CPU watchdog off and see if I get different results.