It couldn't hurt. I don't have problems like that.

mdutil -E -a

That command will erase and rebuild Spotlight index on all volumes.

Since Tahoe, Spotlight has multiple modes. You might have better luck forcing it into folder & files mode. That's command-2. So command-space, spotlight UI appears, keep holding command key, press 2. There's also 1 for applications only, 3 for "actions" and 4 for clipboard history.