What makes my Anki suddenly so slow?

Linux 5.19.6-arch1-1
Version ⁨2.1.55 2.1.54 (both are tried)
Python 3.10.6 Qt 6.3.1 PyQt 6.3.1

I closed other applications, disabled all the Add-ons, restart, and test some cards with a template that has 22 fields, but only 4 of them were filled, each with one line. When viewed via previewer, when I click another note in the browser, it takes an average of 7 seconds for the previewer to refresh. It’s unbelievably slow.

Points that might count in

  1. Recently I imported a large number of notes, now there are 291,969 in total.
  2. The number of fields range from about 20 to 120.
  3. The media folder contains 87,393 files, totaled up to 2G.
  4. Now I only have about 18G free space in my disk.

Anki used to run very smoothly on my laptop before. What could be the cause? It’d be really great if it can run smoothly again.

Have you tried the Anki package directly from the Anki website?

No I didn’t. I used AUR versions.
After some regular updating on other packages, though I cannot pin down what did the trick, my Anki is working excellently again.