Read somehwere (ochokun?) that the mere presence of POTUS on the ground is accompanied by radio-frequency scrambling.
Not so sure myself since so many of his security peeps depend on RF to keep him safe.
Tho, that would make for a pretty good excuse to jam Biden’s “support”.
It’s no octo-secret that everywhere that Potus goes there also goes electronic countermeasures:
https://en.wikipedia.org/wiki/USSS_Electronic_Countermeasures_Suburban
The barrage jammers should be very effective against 2.4 GHz wireless stuff like Bluetooth and wi-fi, but they also have jammers specific to those services. IEDs, missiles, and drones pose a much more serious threat than an old man with a bug in his ear ;-)
https://www.politico.com/magazine/story/2015/01/the-secret-service-is-jamminsort-of-114647