Email DNS Issues after Transfer to AWS Route 53

I recently transferred my domain, asimov.au, from Google Domains to AWS Route 53. As a result, I'm having issues with receiving emails from some senders. My email is through Google Workspace.

In addition, some websites (such as StackOverflow) are flagging my email as temporary and not allowing me to sign up.

I am also seeing some confusing and contradictory results on various DNS lookup websites.

The following tools are reporting the correct records:

DNS Checker* MX Toolbox The following tools are not showing the correct records:

NS Lookup Google Toolbox *DNS checker is showing that the MX records have not propagated to all locations, despite being well over the 48 hour mark.

I've done the following to try to resolve the issue:

• Exported the DNS records from Google Domains and imported them into a hosted zone in AWS
• Waited 48 hours for propagation
• Used Google and Cloudflare's purge cache tools to request a purge for the domains on their servers
• Verified the domain in Google Workspace, which successfully found the MX records, and ensured payment is up to date
• Ensured settings are correct as per this answer

The domain settings in Route 53 are as follows:

And the zone is configured like so:

Note: I added the apex A record pointing to loopback as a test to see if it's propagating