How to make Apple Watch Stop SMS/Message Notifications from Unknown Senders?

I receive a lot of SMS/Message Scams (perhaps 3 or 4 per day). I assume it's related to something like the [flubot virus](https://exchange.telstra.com.au/getting-strange-missed-call-sms-messages-heres-how-to-avoid-the-flubot/) . I like turning the option under settings - notifications messages - customize notifications - unknown senders to off. This stops the phone notifying me when I receive sms from unknown senders. I also have an Apple Watch Series 2 which is set to mirror iphone notifications for messages. But on the Apple Watch I still receive these notifications. **How can I stop receiving notifications from unknown senders on the Apple Watch?** I was also wondering whether this was an issue specific to Series 2 given that it seemingly doesn't get software updates anymore. Ideally I don't want to turn off notifications from messages in general, as getting important sms on the Watch is one of the most important features for me.