Creating a video is sluggish, bug with text effects and download taking hours

I've been having an absolute nightmare trying to produce a video these past couple of days. Firstly, it is running so slowing! I click something and it takes forever for it to even focus on it. I press play and it takes about 30 seconds just to start playing. Just plain terrible.

Secondly, I've been overlaying text on my video at various points, but unfortunately it seems that the shape behind my text is not generating properly:

If I then click on it again to edit it, it does show it correctly:

However when I download the video, it's not generating it correctly there either:

It's weird because the earlier text in the video, with the exact same animations are working fine:

But another one further ahead in the video, again with the same settings, it initially displays with no Shape, but then it appears randomly (video recording attached).

I would also like to add - it takes hours to download. I've never had this issue before, and I've tried the whole closing the page and re-opening, clearing cache/cookies, logging out and in again. Just generally getting a pretty terrible experience in Adobe Express now.

Here is the link to the video in question on Express: https://new.express.adobe.com/id/urn:aaid:sc:EU:d10d6ade-3a03-4c09-90e2-59a846c46050

I'm using Microsoft Edge Version 131.0.2903.99 on Windows 11.