The broken flange is the most likely cause. Since both ordinary and reinforced rings have failed, I’d fix the flange and make sure the bowl is properly supported before trying another seal type.

A wax ring normally lasts for decades. Yearly failure suggests movement or an incorrect fit. Even if the toilet feels firm when you check it by hand, it may shift slightly when someone sits on it. Wax compresses but doesn’t spring back, so that movement can leave a gap where water leaks. [Oatey’s flange repair guidance](https://www.oatey.ca/faqs-blog-videos-case-studies/blog/how-repair-toilet-flange)

For a lasting repair:

- Repair or replace the flange. If only the mounting ring is broken, a suitable repair ring anchored into sound flooring may be enough. If the drain portion or pipe connection is cracked, it needs replacement. While the toilet is off, check the flooring for soft spots or rot.
- Dry-fit the bowl without a ring and add plastic toilet shims wherever it rocks. Get it stable before installing the seal; the floor should support the bowl. [Korky’s installation guidance](https://www.korky.com/toilet-repair-help/why-is-my-toilet-wobbling?retailer=home_hardware)
- Check the flange height. Ideally, it sits on top of the finished floor. If it’s recessed, a standard wax ring may not compress enough to seal. Use a suitable flange extension or the seal thickness specified for that height. [Oatey’s wax-ring guidance](https://www.oatey.ca/faqs-blog-videos-case-studies/blog/oatey-101-wax-rings)
- Remove the old wax, install a fresh ring, and seat the bowl without rocking it or lifting it again. Tighten the mounting nuts gently and evenly. Overtightening can crack the porcelain. [Oatey’s installation instructions](https://www.oatey.ca/faqs-blog-videos-case-studies/blog/how-repair-toilet-flange)