With OLED monitors, pixel cleaning is basic user maintenance. So, if you don't do it often, the problem will recur.
I would check the manual and see if there are automatic settings for pixel care.
This is the case for all OLED monitors and TVs, due to how OLED operates. Personally, I own an Asus ROG Swift OLED PG32UCDM, and there are a bunch of settings to prevent this from occurring. I'm sure Samsung has similar options.
https://www.samsung.com/au/support/tv-audio-video/using-panel-care-on-your-samsung-oled-tv/?srsltid=...