Thanks, guys! Got the chap running. Extra thanks to Henrik for pointing out that Ch_PD I/O needs to be pulled high. I had missed that.

Serial comms with terminal work ok.

Can see the module on my Android.

COULD see the routers (mine, and ones in the vicinity) with the AT+CWLAP.

Could connect with my router after specifying SSID and the password.

BUT, after that, AT+CWLAP no more lists the routers around; module seems to hang with a "busy now' response to any query.

All other AT commands still work.

Wonder what is happenning? (Module is connected to my router, confirmed that using AT+CWJAP?)

Wonder how to erase my router from the module's eeprom? That might make the AT+CWLAP start listing the routers around again.

Perhaps time to enlist on the ESP82666 forum.