Unable to connect to my owncloud from app

Actual behaviour

I installed my owncloud server on linux machine with https://owncloud.xxxxxxxx.tk:10443 (freenom), when i connect via browser from my androidphone the site respond correctly, if i use android app it is not respond, if i instead insert in the app the ip instead of my registered name, it is respond correctly. if you see the dig of google dns the resolution is good.

alessandro@debian-z230:~$ dig @8.8.8.8 owncloud.xxxxxxxx.tk

; <<>> DiG 9.16.13-Debian <<>> @8.8.8.8 owncloud.xxxxxxxx.tk
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 40628
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;owncloud.xxxxxxx.tk. IN A

;; ANSWER SECTION:
owncloud.xxxxxxx.tk. 3599 IN A 2.xxx.xx.xx7

;; Query time: 59 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Tue Apr 13 20:14:48 CEST 2021
;; MSG SIZE rcvd: 65

Could you help me to understand why?