After a while the browser starts to lag

[ARRA]

No, the 3 months limitation is hard coded in Chromium.
There is some discussion:
https://www.reddit.com/r/chrome/comments...r_then_90/

Are you using Google account sync?
Maybe the download records contain the records from other computers.
By the way, have you ever shut down your computer abnormally?

Yes, full sync, but I only use one computer.
And yes, there were abnormally shutdowns when I was overclocking, but the browser did not start lagging after that. Last time (about a year ago), he also lagged, but I don't remember abnormally shutdowns.
Again, clearing the history solved the lag problem, so I doubt that the problem is in the corrupted file.