Ethernet port on iMAC 27" computer stopped working after HP Wireless Printer install

I just bought a new iMAC 27" computer running BigSur operating system and connected to the internet with the Ethernet port (RJ45 jack) on the back of the computer. Everything was working fine. Now after installing a new HP printer/scanner (HP Laserjet MFP M234dwe Wireless Black White AllinOne Printer), using Wifi, I can no longer access the internet via the Ethernet port. The Ethernet connection is no longer recognized. I rebooted the Netgear router/modem and all the connections are secure. All the cables work. Why have I lost my access to the internet via the cable using the RJ45 jack? Has the HP software corrupted the Ethernet port? How do I get my Ethernet port working again. BTW the Wifi connection is good. If I turn the Wifi off, I lose my internet connection and still cannot connect to the Ethernet port. Do I need to purchase USB A or Thunderbolt 3 (USB C) Ethernet adapters to connect to the internet? Any help is much appreciated. Thank you.