I generally use two (2) devices to upload images to Wikimedia Commons, I use a Microsoft Lumia 950 XL phablet for uploading images from other websites to Wikimedia Commons on which I mostly use the Microsoft Edge web browser. And I use an Elephone P8 Mini mobile telephone 📞 for my own photography (as the camera on my ML950XL is broken) with the Ecosia web browser, when I use the latter I insert text in the field "Caption" while using the MediaWiki Upload Wizard and after publishing the file captions appear to the attached files.
Meanwhile when I upload an image using my ML950XL with Microsoft Edge, where I also use the mobile version of the MediaWiki Upload Wizard, the page says "submitting captions..." during the upload phase, but after I open the file page no captions seem to be present nor am I performing the edits (despite the MediaWiki Upload Wizard telling me otherwise) and the files get published without any errors.
I've run into this issue since about April 8th and it only seems to affect Microsoft Edge, I have not tried it using Microsoft Edge on another operating system or form factor so this might be an issue with the browser or not.