If your phone cannot connect to Fi's servers due to poor LTE-M/Wi-Fi, you will see a banner at the bottom of the Live Tab that indicates Poor Phone Signal - (your pet's) location data is delayed.
What Causes This Alert and How to Resolve It
This alert is related to your phone's ability to receive data, not to your Fi device's performance:
If there is a Wi-Fi network available, we recommend connecting to Wi-Fi to improve your phone's connectivity. You can learn more about improving connectivity here.
If you are in a location with poor LTE-M (meaning poor mobile service), we recommend keeping a close eye on your pet, as you may experience delays in remote tracking.
Once you are in a location with improved GPS, LTE-M, and/or Wi-Fi, this alert will automatically disappear.