OP, we are trying to help and understand why the meanings of our questions might seem odd. But they're directed towards helping you and so far, I for one am confused.
If a motorist parks in a bay such as yours they should be issued with a code 16 higher level penalty because it's a permit holders only bay. But London councils often don't when dealing with their own resident permit holders because 16 has to carry the higher level penalty. Instead they use code 19(lower level) which is a derivative of 16 and its sister, code 12. This confuses the average motorist. If you're interested, here's the list:
https://archive.londoncouncils.gov.uk/download/file/fid/28636A PCN must state:
e)the grounds on which the civil enforcement officer serving the notice believes that a penalty charge is payable;
According to your PCN, there's no way that the grounds can be reconciled against any list, schedule, regulation or guidance which I know.
Invalid permit? You either had one that was at one time valid for this parking place or not. Are Lambeth taking liberties with the narrow definition of 'invalid' to include any resident permit holder who is parking in a bay reserved for other permits? This is not their prerogative, it's the Mayor of London's.
Electronic payment -