Thanks for the suggestions. Linux (Manjaro) laptop, using Firefox. Ad-block software disabled for that 'site'. Download to my heart's content from other sites :-)
Did work many moons ago - hadn't attempted a download for circa 6 months. Been trying periodically over the past few weeks, every time it fails (even after a full power-cycle of the system - inverter & battery - as recommended by Octopus [am on IOF]).
Complete red herring(!), but baffled why I keep seeing (many) of these messages in the Log:
2024-09-21 12:16:55 You Enable Eco Mode Inverter Timeout false -1 API - Inverter Settings
Obviously all coming from Octopus, so baffling with me being on IOF. (Perhaps I should raise this in a separate thread.)
BR, Jon