Hey StarsSaphire,
We understand you're experiencing WI-Fi disconnects or issues joining on your iPhone 8 running iOS 14.
To clarify, are you running the latest version of iOS, iOS 14.0.1? If not, we'd recommend backing up and updating to it. If you already are, and continuing to experience this behavior, we'd like for you to complete the following:
Go to Settings > Bluetooth and turn this feature off. Do not do so using Control Center. After disabling, test to see if the disconnects or issues joining the network persist. If so, we'd also like for you to go to Settings > Cellular and turn off LTE and test further.
If you continue to have issues, or disabling one of these features resolves the issue, we'd suggest contacting Apple Support for further help here:
Get Support
Take care!