System freezes when launching Firefox?

Question

linux

There is a Firefox 65.0.1 x64 browser installed on Linux. At the first start after turning on the PC and loading Linux, the system freezes for 15 seconds. Moreover, if you open any bookmark, it causes a freeze twice as long.
The hang is due to the fact that there is a load on the disk subsystem. Something is intensively read or written. All this only happens the first time you start Firefox after turning on the PC, and only after opening the very first tab. Also it happens on Linux but not on Windows. And it started when I installed an SSD under the system. Before that, she stood on a regular HDD and nothing like this was observed.
Has anyone encountered a similar phenomenon? What could it be and how to fix it?