It still could be an issue with Weather Underground. You mentioned you had multiple API keys. You might try deleting all of them and then use the "Regenerate Key" option under "Member Settings".
As I mentioned in post #215 of this thread the issue of missing plates is not due to anything with this app.
The log file doesn't show anything in regards to missing plates, but I have noticed an issue with the timestamp. It is off by 5 hours.
@algertc would it be possible to add an edit option to the license plate image? Something like the mockup below would make it a lot easier to edit a plate number.