Meta fields disabled with CPT having underscore

Hello,

Thank you for that additional information, and sorry for the delay.

I’ve tried creating a CPT on my end but I’m unable to replicate this issue using an underscore in the slug:
https://i.rankmath.com/jKP3WG

Please let me know if I have missed a step to replicate this. However, assuming you are using the latest version of all the plugins and the themes (please update if not yet), it would seem like a conflict with one of the plugins or the theme you are using.

To determine that, please follow this troubleshooting guide:
https://rankmath.com/kb/check-plugin-conflicts/

Only the site admin would know and your users won’t be affected by this troubleshooting.

If the issue persists, please edit the first post on this ticket and include your WordPress & FTP logins in the designated Sensitive Data section.

It is completely secure and only our support staff has access to that section. If you want, you can use the below plugin to generate a temporary login URL to your website and share that with us instead:

https://wordpress.org/plugins/temporary-login-without-password/

You can use the above plugin in conjunction with the WP Security Audit Log to monitor what changes our staff might make on your website (if any):

https://wordpress.org/plugins/wp-security-audit-log/

Please do take a complete backup of your website before sharing the information with us.

Thank you, and we really look forward to helping you.

Hello,

Thank you for that additional information, and sorry for the delay.

I’ve already passed this issue to our dev team and will get back to you shortly. We really appreciate your kind patience regarding this matter.

Meanwhile, please don’t hesitate to contact us anytime to assist you further with anything else.

Thank you.