trouble installing HP8730 printer

My HP 8730 printer is installed and working properly on one Mac Pro, but won't install properly on a similar machine. The printer is turned on, connected wirelessly to my local network, and appears when I "Add Printer" using the Printers & Scanners (Under System Preferences). After I click "Add" button, and it says "Setting up 'HP OfficeJet Pro 8730 ....." ithere is an error: "Unable to verify the printer on your network." It also says "Unable to connect to ‘HP OfficeJet Pro 8730 [4350E2] (15671)._ipps._tcp.local.’ due to an error. Would you still like to create the printer?" with Cancel or Continue. I press Continue and it says "Setting up the device...". FInally it says "An error occurred while trying to add the selected device." "Unable to communicate with the printer at this time." with a Cancel button. Meanwhile, the printer is on, connected, and usable on my other machine. I've tried the option to 'Reset Printing System' using Printers & Scanners. What next? thank you

I'm running MacOS 10.14.6 on a Macbook Pro 2018. The printer has worked on this machine in the past, though I frequently had to delete and re-add it. Now it doesn't complete the setup (as described above).

I used the CUPS web interface to try adding the printer. It was identified on the wireless network and added (seemingly) without errors. When I use the Printers page, Maintenance>Print Test Page, I see the following message:

processing since
Tue Aug 4 05:49:36 2020
"The printer is unreachable at this time."