Also, try resetting Illustrator's preferences by following the steps shared in this article (https://helpx.adobe.com/illustrator/kb/troubleshoot-preference-issues.html) and sharing your observations. Disclaimer: Please note that resetting preferences will remove all custom settings, and Illustrator will launch with the defaults. You may take a backup of these settings from the location mentioned in the article.
As I already said, it did not behave in that way for files generated within Illustrator. I also said that I had updated the GPU drivers. However, I have just reopened the pdf in Illustrator 2023 (for about the 5th or 6th time) and now animated zoom is working. Case closed until the next time!!