I Locked my lost phone with Find My Device, then Found it with shattered screen. Cannot connect with PC to retrieve data

My New Samsung phone was lost or stolen. I searched for it, using Find My Device app and Found It in a Motel Parking Lot with shattered screen. I had locked the device, during the locating process, and had created a Text to provide contact info, should someone find it. Once I had it back home, I used the “My Phone Companion” app and found I was still able to connect with it, with my PC. I had Full Use of the phone, using this app, but a few hours later the connection was lost and have been unable to regain connection. I’m unsure why the connection was lost, in this delayed fashion. I need to retrieve Data, as the phone was insured, and is to be repaired or replaced. The Repair Center has told me they Will Not attempt to Retrieve and Transfer Data, as it is My Responsibility. I am wondering WHY MY PC CAN NO LONGER CONNECT WITH IT, even if I use the USB Port and hook up direct. I’m unsure of how to retrieve the data and transfer it into the phone, once repaired or replaced. I could use some advice and instruction!!