I also got the same problem with pluggins,
Please look in the attachment, I have have uploaded the theme "elegant" but it doesn't appear in the theme available. If I try to upload it again, it says that the theme is already there.
I did the same with the pluggin "privacy" as it is discribed in https://docs.oxwall.org/install:plugin but it doesn't show up in the avalaible pluggin page.
Can you see my problem?
Thank you in advance,
Kind Regards,
Niko