Just wanted to update everyone here - this was a confirmed chromium issue affecting versions greater than 128. This includes any browsers based on chromium (which is the vast majority of them, especially on Android). Firefox (the only major exception) on Android doesn’t support (and has never supported) drag and drop, but that is completely unrelated.
However, the issue is now resolved in the most recent build of Chrome Canary, v132.0.6807.0! You can get that from the Play Store and it may require a manual update since it’s a brand new version.
We’re hoping this fix will be brought into the main/production chrome browser (and therefore the version distributed/wrapped by other browser makers) in the coming weeks/months.
I’m closing the thread here, if you want to keep up with this you should follow the issue over on the Chromium bug tracker: https://issues.chromium.org/issues/363930156
Thanks to everyone (here and on Discord) who helped us track down this issue and file a report.