I recently got Lulzbot Taz 5 and installed Cura 3.6.37version. I connect the printer and PC with USB port, but it says that PC couldn’t connect to the printer. Note that using Printrun I can control very well the printer. But what can be the problem with the Cura application?
Try manually selecting the printer’s COM port in Cura, but also remember that if Printrun, Pronterface, or other software is running and connected to the printer, Cura won’t be able to control the COM port to connect to the printer.