DX5401 purchased from Wind3 Italy slow administration webpage

I have had this router provided by wind3, for a year and it has always had the terrible firmware V5.17(ABXA.1)b7 since I installed it.
Never any bug fix update, or security patch update.
The biggest problem is the extreme slowness of the router administration web page if I change the wifi password to one not directly assigned by the ISP and Poor stability of the wifi.
Would it be possible to provide a newer firmware? (V5.17(ABYO.1)C0)
I have also read about the vulnerabilities CVE-2022-26413 , CVE-2022-26414
It seems absurd to me that a Zyxel equipment is not as reliable and up-to-date as it should be, even if provided by an Internet Service Provider.