Safari on macOS 15.3.1 shows “cannot parse response” (NSURLErrorDomain:-1017)" error

I run a couple of Wordpress page and the error often occurred after editing a few pages, I would need to relaunch safari to get it working again. But there's no problem with Chrome. Tried setting google VPN as mention by some online source but no luck.

PS: The problem starts to occur after updating to new Mac OS Sequoia.

Currently running: Mac OS Sequoia 15.3.1, Safari 18.3 (20620.2.4.11.5)

[Re-Titled by Moderator]