Problems loading email content on iPad mail

You're very welcome.

While Private Relay is an iCloud+ exclusive feature, it is understood that the same infrastructure supports other services, such as Protect Mail Activity.

Do you have a VPN App or profiles installed, or a security/AV/firewall App such as Norton installed. If so, these may be unexpectedly interfering with your network connection.

In such circumstances, the resolution is usually simple; if installed, you may only need to temporarily disable or remove the Security App and/or VPN.

Just a hunch, but are you using Apple's Private Relay, or Mail Privacy Protection features?

Settings > [Your Name / AppleID] > iCloud > [iCloud+] Private Relay > Private Relay - set to ON or OFF as required

Settings > Mail > [Messages] Privacy Protection > Protect Mail Activity - set to ON or OFF as required

Either of these settings might influence the issue that you see. If either are enabled (i.e., ON), as a diagnostic exercise, you might try setting them to OFF.

You should note that as email messages have already been downloaded without the embedded images, the change will not resolve the problem for mail messages already delivered to your iPad.

Further info:

Apple - Support - System Status