Apparently there is a fix for bato (even if it's a bit tedious because you have to open the pictures in another window on your browser and change "k" to "n" on the web address of the picture) but not for mangago. The problem is the hosting program/website, that just doesn't load the picture properly.
It feels like when some times ago, lots of websites crashed because a security server/website went down.
There is a fix for mangago as well!
Basically, for the chapters that have broken/missing panels (because those are chapters uploaded by bots from bato), the problem can be fixed by opening the chapter whole page on incognito mod in either chrome or opera (I don't know about other browsers). I've read it on reddit and it works so far for me.

Is the site broken, I've encountered a lot of missing panels lately