Private xfinity wifi network slow since adding xfinity mobile service

My private xfinity wifi appears to be much slower for streaming since I've added xfinity mobile for my cell phones.  Both phones connect to my private wifi network. I'm wondering if I should have my phones connect to my home XFINITY hotspot instead. I tried to do this, but it's asking for a certificate. When I searched this forum the solutions appear to exist in  private separate emails.

Thanks,

Russ