Smart Device Connectivity

I just purchased a G54 and went through all the setup and activation with Spectrum. No issues, much more stable connection all is well. Until I had to swing all of my smart home devices over and many are having issues with the connection. My thought is the 2.4ghz vs the 5ghz may be the issue? I’m curious if anyone else knows how to remedy this? Most devices are a Google based platform and the previous router/modem from spectrum had no issues. I’ve gone through all the troubleshooting with Google and nothing seems to work. The only thing that has changed is this setup so I have to assume it’s to blame. Any help would be greatly appreciated.