Cannot connect the server through IPV6

[South-River]

Steps to reproduce

1.PHP=7.4.30, MySQL=8.0.30, Nextcloud24 runs on Ubuntu, Latest version of Nextcloud App in IOS
2.Connect the Server

Expected behaviour

It should connect successfully, and then allow me to log in.

Actual behaviour

I can't connect it on app in ios. However, I can connect it on my Android app, and also connect successfully on chrome in ios.
Link like this

http://[240c:7281:7287:8454:7120:a2d3:bd4c:830d]:44444/nextcloud/nextcloud  //the IP here is not my IP

Screenshots

My system Language is Chinese that I suppose you can't read it. It gives me a message like below

Link Error
Can't find the server using this address

Logs

I think there's no log since I even can't connect the server.

Reasoning or why should it be changed/implemented?

Environment data

iOS version: iOS 15.6.1

Nextcloud iOS app version: 4.4.3.0

Server operating system: Ubuntu20.04

Web server: Apache

Database: MySQL8.0.30

PHP version: 7.4.30

Nextcloud version: 24

[ne20002]

Running Nextcloud 24.0.5 with community docker image behind reverse proxy. No problem connecting from iOS client with IPv6 (checked in log).

[South-River]

Running Nextcloud 24.0.5 with community docker image behind reverse proxy. No problem connecting from iOS client with IPv6 (checked in log).

Thank you. May I ask your ios version and nextcloud version? I think this could be the only difference between us.
In fact, I also use nplayer and connect with IPv6 to play videos saved in the server, and it works with no problem, so I think the network should be fine.