Although our several iPad-family devices continued to function throughout our recent Hot Spell… Later… Direct-cable Charging didn't work (even with a new cable) a day or two after local temperatures dropped.
How we solved it: Shut 'em Down & Start 'em back Up.
Dunno why it worked… but we're happy to see 'em all charging, again. :~)
Enjoy!
When in doubt, reboot. The mantra for most electrical/computer thingies.