I have had no problems with tethered shooting using DPP4 and EU3 until yesterday when the EOS Utility would no longer recognize the usb connection to the camera in Windows 10. I had last used remote shooting three weeks ago and had forgotten to turn the camera off, so the battery was drained. When I recharged it, remote shooting would not work. The camera is still recognized in File Explorer. I have tried multiple cables, uninstalled and reinstalled the software, ensured that WiFi is switched off, and disabled auto power off. I also tried to use Adobe Lightroom. Lightroom could import photos from the SD card, but couldn't find the camera for tethered shooting. Is there some other setting I am missing?
"Is there some other setting I am missing?"
If there is a full reset of the 5D Mi IV to factory default is a good idea. If Windows is seeing the camera I se no reason why LR will not. I use tethering all the time with LR and it works flawlessly.
"... the battery was drained."
You may need a new Canon brand battery. It may have the giddy up and go for the camera but not anything else. You have tried a lot of simple stuff you need to check the battery.
12/05/2023: New firmware updates are available.
09/26/2023: New firmware updates are available.
08/18/2023: Canon EOS R5 C training series is released.
07/31/2023: New firmware updates are available.
05/18/2023: New firmware updates are available.
03/30/2023: New firmware updates are available.