Good catch! Firewalls from AV software on your computer, your router, your ISP, or another device or step in the path between you and your website could be responsible for this.
Some pages on your site also seem to be listed by Google Safe Browsing to be deceptive pages (i.e. phishing): Google Transparency Report
How can I get it taken off Google Safe Browsing, I think it is because of my login page, but it uses Google’s Firebase systems, as well how would be able to my website from the antivirus blacklists?
If you sign up for Google Search Console and register your site, you can get more information about what content was actually flagged, and request a review.
You’d have to check with every anti virus company if your site is listed, and see if they have a review procedure you can use to request an appeal. But I wouldn’t do that, it takes a lot of effort, and no guarantees that it will resolve the specific block you are experiencing.
Instead of trying to get your site reviewed by a bunch of unrelated companies, maybe you could take this up directly with your ISP instead?