I've seen it once or twice, but it's always connected eventually. Try turning off bluetooth & WiFi (on your phone) and then turn back on. Then go through any prompts on your phone to complete the connection.
I'll also ask, do you have a VPN turned on? I know my VPN will prevent phone from connecting to SYNC.
2021 Broncos - BaseSquatch 4dr. Rapid Red V6 Soft Top
Big Bed 4dr. AMB V6 Soft Top Tow (BIL's)
Nitto tires SUCK! You've been warned.