To elaborate further on this, the same thing happens when I create a new page, AFTER creating a new section and inserting an element into it. When I create a new section and DO NOT INSERT an element I can save it just fine.

Weird...

From console I got the following error:

Uncaught (in promise) Object { stack: "j@https://xxxxxxxxxxxx/joomla/administrator/components/com_sppagebuilder/assets/editor/dist/js/vendors.min.js?2abb743fdfce533d33d8c0eb7ff5cefb:2:1139962\n2861/we.xhr</</u/<@https://xxxxxxxxxx/joomla/administrator/components/com_sppagebuilder/assets/editor/dist/js/vendors.min.js?2abb743fdfce533d33d8c0eb7ff5cefb:2:1153661\nu@https://xxxxxxxxxxx/joomla/administrator/components/com_sppagebuilder/assets/editor/dist/js/vendors.min.js?2abb743fdfce533d33d8c0eb7ff5cefb:2:1153806\n", message: "Request failed with status code 403", name: "AxiosError", code: "ERR_BAD_REQUEST", config: {…}, request: XMLHttpRequest, response: {…} }

Hello takis,

Thank you for reaching out to our technical support forum and sharing the solution. It will help the people with the same issue.

If there's anything else you need assistance with, feel free to let us know!

Best regards