Main Drain woes.

Just bought a home with a pool. A dream come true! Learning a lot, and also finding a lot of issues. My pool has a flow valve, turn it all the way to the right, I get all suction from the skimmer, all the way left, I ‘should’ get all suction from the drain. But all the way left does nothing. No water flows through at all. Is it possible that the previous owners plugged the drain to shut down the main drain? Is this normal? Anyone have any thoughts as to what might be going on. The drain is in the deep end - 6’ deep. Is there something I can look for there?

It’s possible that the drain is plugged for one reason or another. Maybe they discovered that there was a leak in the main drain pipe and it was more cost-effective to plug instead of repair the pipe. Could you post a picture of your plumbing?