Distortion on 15 meters using WSJT-X.

Looks like switching power supply noise, This can be caused by Wall warts, Station Power supplies, UPS 's, furnaces, Washer machines, LED light bulbs, Solar panel inverters and chargers, Televisions you name it.

If you have solar panels with Microinverters your out of luck unless your installers can be pressured into swapping them out with RF quiet Microinverter.

To test this put the Radio on a 12V Battery and, then turn off the AC Power to the whole house if it is gone then it is in your house somewhere if it is in your home then turn ALL the sub breakers OFF and turn the main Breaker on, Make sure you still don't have the noise, do this after each step and if it is still quiet turn one breaker on at a time checking the radio for ANY noise after each breaker is turned on, then go to the next breaker and repeat the test when the noise comes back on then unplug / turn off all the devices on that breaker and then plug them in one at a time, when the noise come on you found the culprit.

If you have close neighbors it may be in your neighbors home it could be coming from your neighbors and good luck with that.

As strong as the Signals are I would bet it is in your home somewhere.

hope this helps