The fact that its regressed and repeated so many times now that clearly it indicates a trend and pattern of abuse by malicious intention. Change management isn't hard, unit tests are not hard, consistently breaking only certain browsers seems targeted.
Notably there are mainstream browsers that have this problem as well. Mozilla Firefox for example. Their Challenge has broken large swathes of the web many times to the point where companies hosting apps and websites have simply said they will not support any browser other than Google Chrome/Edge.
Anytime the market gets sieved and pushed to only one single solution, its because someone is doing it for their benefit to everyone elses loss.
Cloudflare should be broken up in antitrust as a monopoly, as should Google.