Neil and Sara, thank you both! Last night, before seeing your posts, I began testing again while in a different location (happens to be much more remote). I switched to Bypass mode last night, and it appears to be working! Now back in my office in the city, it works as well. I’ll attach my logfile as an fyi.
The above sketch displays firmware version 11051. I should probably buy the XBee3 TH development board.