iOS client files take a long time to upload to the cloud

I have a problem with iOS clients.
Through the official Nextcloud application and web interface, it takes a very long time for photos/videos/documents to be uploaded to the server, 4 photos can be uploaded in about five minutes. Clients on Android and Windows are doing well, everything works quickly.
I installed Nextcloud AIO (ver. 29) + Nginx Proxy Manager (ver. 2.11.2) according to the instructions (GitHub - nextcloud/all-in-one: πŸ“¦ The official Nextcloud installation method. Provides easy deployment and maintenance with most features included in this one Nextcloud instance.)
I found a thread with the same problem, but there is no answer there. ( iPhone iOS Uploads Extremely Slow )
Help me find out what the reason is, please…

Can you tell us someting about the network setup?
Could it be WIFI related? Other clients are connected by Ethernet or not?
Try to find out if there is a network issue. (Ping, tracert, etc)