However, it seems that this feature might be broken in the iPhone 13. According to a post on Reddit, it appears that there are quite a few users who claim that the unlock with Apple Watch feature is not working when paired with the iPhone 13.
According to the thread starter, “So I have an Apple Watch SE and just got my iPhone 13 Pro today, both of which are fully up to date with the newest iOS updates. Whenever I try to enable unlock with Apple Watch on my phone I get an error saying ‘Unable to communicate with Apple Watch’”.
Keep in mind that as far as we know, this only seems to affect the iPhone 13 models. Users are claiming that it worked fine with older iPhone models until they upgraded to the iPhone 13, after which the feature appeared to stop working. We’re not sure if this affects all iPhone 13 devices or if it is limited, but it is clearly a bug and one that hopefully Apple will fix ASAP.