Contents are not displayed

Hello Support, there is the problem that already inserted content is not displayed if you want to edit it again later. We have the problem with both text and images. Once these are inserted and you want to continue working on them one or two days later, these contents are no longer visible in the editing. Here is an example where a video is embedded and text: https://prnt.sc/vuvxpl Here is how the not working editing looks like: https://prnt.sc/vuvxzt Here is an example with text: https://prnt.sc/vuvygh Here is an example of how the editing does not work: https://prnt.sc/vuvyo3 Here is an example with image and text: https://prnt.sc/vuw2k7 Here's what the broken edit looks like: https://prnt.sc/vuw2ob How do we solve this problem? Kind regards