Cut stew meat into smaller slices. I use kitchen shears for this task.
Set your Instant Pot to the saute setting.
Add olive oil, garlic, celery, and onion. Saute until onions are translucent.
Add beef. Brown beef, but don't worry about cooking it all the way through.
Add sloppy joe sauce, Worcestershire sauce, tomato sauce, and brown sugar. Mix everything together.
Close Instant Pot and secure lid. Set the pressure release valve to "sealing"
Cook on high pressure for 8 minutes.
Quick release pressure
Set the Instant pot to the saute setting once again to thicken the sloppy joes.
Saute for about 10 minutes, stirring every few minutes until the sloppy joes are thickened
Build your sandwiches and serve!