Is my ISP messing with my LibreCMC router?

After plugging LibreCMC router in and putting strong password, I made a screen of used memory: https://trisquel.info/files/MemoryFresh.jpg
Then connected it to WAN through pppoe and next day used memory of router has changed to: https://trisquel.info/files/MemoryLater.jpg

I have recently changed out my old Cisco router, it had strange issues, connected to google websites, while all other webpages seemed to be down. This occured on 2 laptops, while my PC had no issue, next time, no issue on one of the laptops, while other computers couldn't connect to any thing except google, youtube.

Another problem with old router was WiFi disconnected randomly, making gaming unpossible. Now my LibreCMC router repeats this problem. No disconnects with wired tho.

Would be nice to receive any thoughts, suggestions, possibly literature to study regarding safety of router and maintenance.

I think this is my ISP admins messing with me, had a funny but unpleasant experience few years ago, during breakdown, in my desperate search for EU contacts on human rights issues, had "Aaa..." key written in any where I tried to write. Threw my laptop to garbage can that day xD /sob

Now for me to be more informative on issues my router has, I can provide more screens, or code, if only I knew what and where to look for.

Also if you find this too much of a hassle to deepen in, but have a literature, please share it. Thank you.