I can confirm that pdf files cannot be viewed anymore when “Hide download” is checked. Instead, the following message is shown: " To view a shared PDF file, the download needs to be allowed for this file share". Viewing pdf files while downloads are prevented used to be possible until very recently.
Is it enough to report this here or should I also open a Github ticket?
EDIT: After unchecking “Hide download”, saving, checking “Hide download”, and saving again, the pdf file seems to be viewable now.