503 problem after updating to WordPress 6.4 (CPU)

Hi,
After updating to WordPress 6.4 we faced extremely high CPU usage and started getting 503 errors. Our hosting provider told us that some themes have this problem after updationg to 6.4. After switching back to the older version of WP; our problem is fuly solved. Any ideas? Suggestions? Should we expect an update for the theme before updating to 6.4?

Hello Anamaria,

I am currently using PHP 7.4 which seems to be the most stable. Is many support forums it is suggested that 6.4 is fully compatible with PHP 7.4. I did try however PHP 8.0 as well; which did not solve the problem. As a matter of fact; it became even slower. I can’t try PHP 8.2 anyway because it gives a critical error on the website.

I contacted the hosting company; they downgraded the wordpress version and warned us about the exptremely high CPU usage. They did a few things to improve speed, restarted our server (dedicated). They informed us that with the update to WP 6.4 they observe high CPU usage problems with certain themes and we should wait for an update from the theme before trying to update to 6.4.

With the downgrades everything went back to normal. Clearly there seems to be a compatibility issue but we are not sure from where it arises.

Your support is much appreciated!

Thank you…

• This reply was modified 2 years by volkandalyan.

Well we tried with 8.0, we will give it another try.

• This reply was modified 2 years by volkandalyan.

No unfortunately, we updated to 6.4 with PHP 8.1, and all we get is 503 Error. We rollback; and everything is fine. There seems to be an issue; not sure exactly what; but once again the hosting company warned us that they are having this issue with some themes after updating to 6.4. PHP version is not the problem here, as I said we tried it with 8.0, 8.1 as well…

• This reply was modified 2 years by volkandalyan.