Transfer drops down to 0 on all interfaces

Hello,
I am getting strange issue on Mikrotik CRS326-24S+2Q+:
https://www.dropbox.com/s/cg6hr73zibfxpyx/Nagranie%20z%20ekranu%202020-01-31%20o%2009.54.38.mov?dl=0
So traffic graph on interfaces looks like this:
https://www.dropbox.com/s/j1b5alr3q9yp442/Zrzut%20ekranu%202020-01-31%2009.49.51.png?dl=0
And it really affects to machines working in these networks.

RouterOS: 6.44.6 long-term
I had such issue many times on routers RB1100AHx2, CCR1036-12G-4S (on various RouterOS versions) and eventually reboot helps in this.
Yet, I really don’t want to reboot this switch, as this is core switch right now. Cannot reboot it during the day.

Any help?