Form fields won’t work in Adobe Reader

I have an extremely basic user-editable PDF built for a client with three fillable text fields. One for the date, one for a title, and one for the text body.

The PDF opens and works absolutely fine in Preview on Mac, but when my client attempts to open it in Adobe Reader (on both Mac and Windows platforms) the text fields highlight blue when the cursor is hovered, but clicking into them does nothing and the fields are unusable.

I've never had this issue before and have produced a number of PDFs with similar basic functionality for this client in the exact same way. The PDFs were made in Acrobat so it seems very odd to me that they can't be used in Reader? I've checked the formatting and everything is absolutely as it should be (it's literally just a text box) and as I say it loads and functions perfectly in non-Adobe PDF readers.

Client is using Windows 11 on their PC and Monterey 12.6 on their Mac with the most up to date version of Reader on both.

Any suggestions?