Unable to apply settings. Please try again. (Ref. 5401)

My domain is:
Previous Studio-GARA.myasustor.com
Now StudioGARA.myasustor.com

I ran this command:
Got some trouble setting the ez-connect, so i did a few factory resets.
Each factory reset was followed by new sertificate
Now when im trying to create a new one, it says : Please try again. (Ref. 5401) I think i reached some kind of limit. I dont know how to acces the old sertificates, nor how to find the private keys for them, so i can try and manualy import one of them.
The goal is to create a sertificate, so i can "secure my connection".

It produced this output:
Please try again. (Ref. 5401)

My web server is (include version):
Asustor NAS AS3304T
The operating system my web server runs on is (include version):
4.2.5.RN33 (this is the ADM version)

My hosting provider, if applicable, is:
Vivacom Bulgaria EAD

I can login to a root shell on my machine (yes or no, or I don't know):
I think so

I'm using a control panel to manage my site (no, or provide the name and version of the control panel):
I`m using the asustor nas app

The version of my client is (e.g. output of certbot --version or certbot-auto --version if you're using Certbot):
I`m not using it