Minecraft Education 1.21.03 won't load macOS Catalina 10.15.7

We were forced to update ME from 1.20.13 as it started saying the client was outdated and it wouldn't open any worlds.

We successfully installed 1.21.03, however it won't load on MacS Catalina 10.15.7.

I can't update my MacOS version as this MacBookPro is an older model.

Any ideas?