(New) Samsung 43" M7 (M70D) Series 4K UHD Smart Monitor

I bought this just to use as a second monitor for a Lenovo desktop PCI and a Lenovo laptop PC. It was incompatible with both. Neither of them could detect it properly, even though a Samsung tech support person insisted that it was "plug and play" and the monitor's diagnostic tests had clean results. I spent eight hours attempting to get it to work, including four of five hours on the phone and messaging with Samsung and Lenovo technical support. My Lenovo laptop has all the most current updates, including device drivers, BIOS, Windows 10 updates. I'm giving up and returning it to Amazon. This model, by the way is a 43" version. The model number on Amazon's product detail page was LS43DM703UNXGO. This is the same as the "model code" on the back of the monitor, which said the "model" was S43DM702UN and the "Type No." was S43DM702U. (Confused? I don't blame you.) Calling this device a monitor seems to be a misnomer. It's more of a complex smart TV that purportedly can be used as a monitor. The remote control is handy, but the user interface appears complex and confusing. For example, its guide to hooking up to a PC -- which appears in an illogical location in the menus -- says that if the connection doesn't work, go to Home > Menu > Connected Devices > Sources > Edit Menu. But there is no such path; there was no "Sources" selection under "Connected Devices."