Cannot add Chromecast to Google home mini

[dpzbatman79]

Recently got two home minis, one for bedroom, one for living room. Easy to set up, but I cannot add my bedroom Chromecast to my bedroom mini to watch videos. It worked well for the Chromecast in my living room. All the Chromecasts are all on the same wifi and I can see them in my Google home app, I just cannot add them to rooms assigned by my home mini.