We also had :
1. Unusually low mail in ballot vote rejection rate (0.02 vs 6% previous elections)
2. Unusually many voters
3. Unusually high turnout in specific areas (90%+)
4. Delay in announcing results
5. Results that don't match (6000 votes flipped back to Trump after "glitch"
Vote rigging: How to spot the tell-tale signs https://www.bbc.com/news/world-africa-37243190