I have user PowerApps to create a custom SharePoint list item form (rather than an App) and need to be able to add attachments to the list items, however when adding the Attachments feature, any attempt to actually upload an attachment to the entry displays the text 'Unsaved' next to the attachment and does not add the attachment upon saving. I have checked another list where a custom form is used and this is the case here also.
Our PowerApps version is 3.19104.33
Could you please advise if there is a way that we can get this functionality working as expected?
Could you please share a bit more about your scenario?
Do you mean that the attached files within the Attachments control could not be saved into your SP List when press "Save" button?
It is an normal bahaviour that -- when upload a file from your local PC into the Attachments control, the attached file would be marked as "Unsaved" until you save your form data back to your SP list.
If you could not save the attached files from the Attachments control back to your SP list, please remove the Attachments control from your Edit form, then re-add it again, re-publish your custom form app, try it again in your SP List, check if the issue is fixed.
In addition, currently, there are some known issue with PowerApps Custom form in SharePoint, please check the following thread for more detaisl: