Hello,
When uploading a large attachment in a side conversation, there is no indication that the file is uploading . This results in thinking that it the upload is not successful as there is no indication that one should just wait. (I opened up a new ticket to send the attachment and here too I realized that it took some time, but understood it was due to the file size because of the progress status bar).
Might be valuable adding a progress bar for uploading attachments in side conversations as well.
Thank you