Cache issue

I have the awesomeweather widget (free version) embedded on home page of https://thakehamparish.co.uk/ (created in March 2016). For months it has worked fine, but has recently developed a cache-related problem. It shows the wrong weather for current day, which can be corrected by manually clearing the cache using the button you provide – but that only fixes the problem for that day (& for that IP address? not sure) and the problem recurs the next day. Manually clearing the cache daily isn’t sustainable. The city link is correctly set up; a click on extended forecast takes you to correct page at openweathermap. Didn’t notice the start of the problem coinciding with any recent change of wordpress version or theme update (Catch Evolution), tho either are possible. Or could it be linked to a conflict with the wpfastestcache plugin, also installed? Help much appreciated.