Modifications made to attachment tab are lost when using browser back button

I can't seem to be able to reproduce this with a final version but on 10.7-SNAPSHOT for example:

• attach a txt file
• click on it to see the content
• use browser back button

-> the attachment is not listed anymore

• refresh

-> the attachment is back

I have the same behavior with both Firefox (61.0.1) and Chrome (68.0.3440.106).

I reproduced the same thing with 10.6-SNAPSHOT just before 10.6 final release, but impossible to reproduce it with 10.6. Using a SNAPSHOT seems to be an important criterion. I guess it's a good news but still...