Video senders are using sold for one of two frequency groups.
The 2.4,ghz ones can get interference from a number of things, from microwave ovens, to other wireless devices like wifi internet signals, or Bluetooth devices.
5ghz ones operate on less common frequencies, so are less susceptible to interference.
SO it wouldsuggest that somewhere, at 1058pm some wireless device is operating close to your AV senders- do you use a wifi tablet or other mobile device (kindle,or mobile etc) connected to wifi in the area? or does someone else?