A relative of mine works in Dubai, so I noticed the following articles about three years ago, which I drew his attention to at the time:
Don't use a VPN in United Arab Emirates – unless you wanna risk jail and a $545,000 fine
Getting caught using a VPN in the UAE will cost you over $500,000
So various media had described a law that came into force in 2016 which basically states that the usage of a VPN can result in high penalties if its use is intended to conceal a criminal offence. My relative is not a criminal, but the text of the law (or the reports about it) allowed so much room for interpretation that there was a certain concern. Later in the year it was made clear that VPNs should remain allowed for legitimate purposes.
On Cloudwards, a web page mentioned recently by @blackbird71, a quite recent VPN recommendation for UAE gives no indication of a blockade of VPN services taking place in the meantime. On the other hand, VPN provider CyberGhost claims that the usage of VPNs in general is forbidden in the United Arab Emirates and advises to cancel subscriptions.
Therefore, the question remains unclear to me whether in UAE Opera-VPN is currently only experiencing a temporary malfunction, or whether VPNs may be blocked in principle after all.
In other threads on the topic Opera + VPN (+ UAE) it has been recommended to check if another of the Opera VPNs works, since several are provided.
If a connection to each of the Opera VPN servers fails, I would install Opera as a portable version on a USB stick (your current installation would remain untouched) and then check with another Internet provider whether the Opera VPN works. This proposal also comes from this forum here.
I'm not an Opera employee, but I think Opera wouldn't present VPN to you in its settings if it were blocked in general in UAE.
Perhaps it would make sense to also mention the ISP in the case of VPN disruptions in the UAE, because different providers could act differently, and in this way problems could be narrowed down further.