This plugin seems to be firing on other events as well, not just on user registration:
Event::on(User::class, User::EVENT_BEFORE_VALIDATE, function (ModelEvent $event) {
Apparently Commerce does a validation check before it updates a cart as well. I believe that line is responsible for the trouble.
We have a single page checkout where people enter their email address and users were getting a "couldn't update cart" with the "email" address they used kicked back as the invalid key with no explanation. It seems that the only addresses it would accept would be email address that were already in the system.
After some troubleshooting, I disabled the plugin and Commerce immediately updated their cart. When people were logged in they also didn't have any issue which makes sense since the user was already validated.
This plugin seems to be firing on other events as well, not just on user registration:
Apparently Commerce does a validation check before it updates a cart as well. I believe that line is responsible for the trouble.
We have a single page checkout where people enter their email address and users were getting a "couldn't update cart" with the "email" address they used kicked back as the invalid key with no explanation. It seems that the only addresses it would accept would be email address that were already in the system.
After some troubleshooting, I disabled the plugin and Commerce immediately updated their cart. When people were logged in they also didn't have any issue which makes sense since the user was already validated.