Ask yourself an objective question, why would they stop counting...

Ask yourself an objective question, why would they stop counting votes in the key States simultaneously, when Trump was ahead

Usual reason.
Those voting on election day had their votes counted first according to the rules.
Trump ahead.
Then they start opening the votes contained within envelopes verifying the signatures.
Once that process completes they process those votes in batches.
As expected those votes favoured Biden as the Dems encouraged and facilitated Covid safe voting.

Trump had pre planned to announce victory at that stage but was kyboshed by Fox calling Arizona early for Biden.
That made trump mad at Fox and so were his fans.
That put Trumpworld in a bad mood.