Last Chatmessage sent disappears until refresh when a conversation is closed and opened, if the said message had an attachment

Reproduction steps:

1. Attach an image to the message
2. Send it
3. Press the back button in the UI
4. Open the chat again

The last chat message disappears for whatever reason and doesn't return until a refresh.

IRC log with more unstructured info:

17:16 <@rinpatch> unrelated, did someone ever experience the last chatmessage you sent disappearing from the conversation until 
                  refresh? happened to me a couple of times both on mobile and pc
17:16 < Shpuld> huh, haven't seen that happen
17:16 < Shpuld> which browsers do you use?
17:17 < Shpuld> WS or http?
17:17 <@rinpatch> chrome on mobile, firefox on desktop. ws disabled
17:17 <@rinpatch> let me see if I can consitently reproduce it
17:17 < Shpuld> strange, I use the chat often and haven't encountered it
17:17 < Shpuld> I assume youRe on a pretty recent version of FE
17:18 <@rinpatch> yup, reproduced consistently by 1. attaching an image 2. sending 3. going out of the conversation and back
17:18 <@rinpatch> my fe is at https://git.pleroma.social/pleroma/pleroma-fe/commit/fa2884a8
17:19 < Shpuld> oh so like before the message is confirmed
17:19 <@rinpatch> wdym? the POST succeeds before I exit the conversation
17:20 < Shpuld> oh
17:21 <@rinpatch> the post with attachment is there on /api/v1/pleroma/chats/:chat/messages request pleroma-fe does on chat enter, so I 
                  am not sure why it's hidden
17:23 <@rinpatch> actually, seems like I had WS enabled on my desktop. didn't have it on mobile and it's reproducible there as well 
                  though
17:23 <@rinpatch> should I open an issue?
17:23 < Shpuld> yes