Alt Text not being read when exported from Indesign

I have multiple PDFs created in Indesign where charts / images have been placed within the text thread and with relevant alt text applied. This was never a problem until recently...

Acrobat now skips the figures and fails to read out aloud the alt text, even with PDFs created previously which had worked fine in older versions of Acrobat, however I haven’t pinpointed exactly when this started.

The screenshot of the tags panel shows the <Figure> tag contained within a <P> tag. My understanding is this is due to the figure having been inserted into the text thread within indesign. Once the <Figure> is placed outside the <P> it works fine in Acrobat, but as I said, this was never an issue. I have 100s of archived PDFs which worked fine previously so would like to find a solution which didn’t require this additional step for every figure.

Hopefully you can help!