Pump primes beautiful and then goes to pot

Help! I am curious if anyone can help me in taking a look at the vide of my pool pump priming and then losing suction and ID what could possibly be the problem. I have gone through the gambit of cleaning everything, changing out o rings and vaccum hoses etc. I don’t know my issue and I am just at a loss. I have a dedicated vaccum line and a skimmer basket that are the intake pipes. I have a Sta Rite filter system with a fairly new motor on the pool pump. It starts off perfectly and then just does not hold that strong flow. Let me know if anyone can help me further troubleshoot.

Pine street pool pump