search engine keeps telling me their systems have detected unusual traffic from my computer network.

This is my first time to Mozilla Support with a question. Firefox is my default browser using version 155.0.1. I use Strict ETP. [FYI - my skills are basic with IT]. I also use Firefox Focus on my iPhone. I previously used Google Chrome but I must have removed it as it's no longer appearing in my desktop Apps. As of a couple of days ago, I tidied up my Library/cache and deleted it to 'Trash', using Apple support community help instructions for housekeeping. (Because I was getting increased frequency in the spinning ball at start-up). I didn't delete any other folders - just Library/cache in my housekeeping. Since then, when searching Google / Firefox, Google keeps asking if I'm a robot (asking me to tick a 'reCaptcha' box) as it's detecting unusual traffic on my computer - before it continues with my search via Firefox browser. This doesn't happen when using other search engines, (eg: Bing or Duck Duck Go). Using Google searches on Safari browser does not ask me if I'm a robot question ? Searches go through perfectly - no questions asked. Only when I use Google search engine with desktop Firefox. Is it my privacy settings? I prefer Firefox as my browser because it's independent and open sourced, safe and for its sense of community. My desktop MacBook Air (2017) is 9 y/o - vintage? So, no longer receiving software updates - but hoping to upgrade with a new Mac desktop soon. (see attached image of current MacBook Air operating system Monterey version 12.7.6). My question is: - Why is Google only in the last two days asking me at every search, the above question about 'unusual traffic' / tick the robot box ? And, - Should I reinstall 'Google Chrome' via the Apple Store? Or for better security, think of getting a new computer sooner, rather than later ? :( Many thanks for your support, and time. [No hurry!] thank you in advance, regards, kindly Rose Roselyn Hansen (Australia)