Yamaha F115B gurgling water under powerhead

[Yama-Aluma]

Hello. I'm new here and hope I'm asking in the right place. I have a 2015 Yamaha F115B that has been great for 5 years. It started making a squealing, belt slipping noise that is apparently common. As other helpful people online suggested I pulled the foot and greased the drive shaft and drive shaft guide bushings. After reinstalling the foot and plunking the boat back in the drink, it now sounds much louder and water is gurgling out of the little opening under the powerhead, the opening that you can see the top of the driveshaft through. I removed the foot again and made sure there wasn't something out of wack. No blockages, the water tube was seated properly, all was good. I did find an old thread online that had a similar issue and the people helping him suggested the thermostat. I checked it and it looks new, no corrosion. Also I hear there are seals under the powerhead that can fail causing this issue but it seems unlikely to happen at the same time as pulling the foot. And help would be greatly appreciated. The motor is 2 months over warranty so I want to try to fix it myself.