Is there a way to control/configure when OSMC sends WOL requests?

My setup: One Pi B+ and one Pi2 (running OSMC) clients, connecting to MySQL on a linux box (mint 17.3) server that exports media via NFS shares.

My problem/question. My linux box get awaken just 2 minutes (or so) after going to sleep (after 30 minutes of no local/network activity). Pulling out the ethernet cable stops that, so I am sure a WOL packet is doing the wakening. Shutting down both Pis also stops the wakening, so I guess the WOL comes from the Pis. So:

When is OSMC sending WOL requests? I know (have configured it to) when trying to access a media over the network. But should it also send WOLs, when I am on the Home Screen on the Weather menu?
Is there a way to control/configure this behaviour?

WOL is a Kodi function. Might be best to address it with them on their forum.

ActionA, thanks for taking the time to post this.

I apologize for not looking hard enough, but now I found this thread and this that describe/question the same effect. It seems MySQL requests are the root cause, not samba/nfs. I 'm going to try the suggested workaround of disabling the “Recently Added” widget.
The other suggestion of moving MySQL DB out of the NAS solution and into RPi is also interesting and more elegant.