Hi There,
Glad you sorted things out. But I can’t replicate this issue on my dev site, login or not search button on navbar works. This could be a plugin conflict, please do a testing. You can do this by deactivating all third party plugins, and seeing if the problem remains. If it’s fixed, you’ll know a plugin caused the problem, and you can narrow down which one by reactivating them one at a time.
Thanks.