I've tried two epson scanners on my mac (os Big Sur 11.4. One connected sporadically and the second wouldn't connect at all.

I'm wondering if I'm missing something? I made sure to set my OS version to 11.4 when downloading drivers from the Epson support site. I tried using Epson Scan 2 and the default OS driver. With the v19, it would scan once and then I couldn't get it to connect after that unless I restarted. I got this error: "Failed to open a connection to the device (-21345)". The v600 would never connect at all. I restarted, unplugged, turn off and on, all that they tell you to on the support site. The scan I managed to get from the v19 was vastly superior to the canon scanner I tried, but if I can't get the scanner to connect, it's useless!