Gmail emails sending but not receiving - issue with MX record?

[nathan-nz]

I have the domain ngstructural.co.nz. I paid for google workspace and setup my email by adding the MX record where I bought the domain. It has been working fine. However today it stopped working. I can send emails but not receive them.

When I go to check if there is an error, I get this message - ok so there is an error...

These are my DNS settings and MX record at the domain website.

But when I try to reactivate my gmail I get this error

How do I delete priority 0? I can't see this at the domain website.

How can I resolve?