I've sometimes had a similar issue with searching at www.startpage.com. It became increasingly frequent during work-from-home, blocking me with a captcha or a false message titled "Just Checking…" (implying they're inspecting something, but actually requiring that you fill out a freeform text box explaining yourself). After a few dozen times, I started appending to the textbox an appeal for a paid version.

When I switched to eu.startpage.com, it stopped treating me like a bot. But eventually it started misbehaving in other ways: more than a page of ads (more than two, on mobile!), inserting the ads at the last moment so that your eyes and sometimes your click or tap would land on an ad. Occasionally, I'd win by searching for something so esoteric that no ads displayed. But later they started inserting results specific to my realworld location for searches that returned few or no results.

I reluctantly removed the adblock exemption for StartPage, which causes them to now insert a plea to support them by enabling ads. I contacted their support, who refused to believe that the had pages of ads, and they had no interest a paid version.

Then I found Kagi, and tried it every once in a while until it matured. I still sometimes goto StartPage's EU site on other computers, but on my own I mainly use Kagi.