I still don’t know why nextcloud.local/ works on my wired PC’s but not my phone. However, I did find that entering the local IP address into my browser on my phone did give a message from my Nextcloud Box that stated I was entering through an untrusted domain. Using the information here I added the local IP address as a trusted domain and I am now able to use my phone (nextcloud.local/ is a trusted domain, I don’t understand why it doesn’t work on my phone the same as my wired PC’s).