1) Are you using the "mobile" version of the editor? Or, the desktop version?
2) Are you uploading the image directly into the post, or is the image hosted outside the post?
3) And of course, the usual: mobile device? browser? version?
1) I'm using the mobile version.
2) I'm uploading the image directly.
3) Galaxy S9+ Android, Chrome V 81.0.4044.96 (I just updated and retested before posting this)