To replicate on any IPS community:
Create File Moderator subgroup, add it to Moderators, give every File/Downloads permission (including hide/unhide).
Post a file where approval is required. Note that the file appears in the approval queue for a user in that moderator group.
Post an update to said file, where approval is required. Note that the file is not shown in the approval queue for this moderator group, nor can they actually approve the file.
I've fixed this on my community so I don't need this to be fixed upstream - but this is a heads up for a bug in Invision Community.