Hi Ken, which PF sheet? Official or community? Regardless, anytime you add additional attributes to a sheet, additional attacks, spells, abilities, buffs, conditions, etc. it will begin to require more memory. Spells often require many attributes per spell added to the sheet, so it's frequently advised to limit the number of spells you keep on a given character. I assume having a large number of active buffs/conditions would have a similar effect. What happens if you deactivate all buffs/conditions? Any change? Browsers can have issues after certain updates (in the browser version as well as roll20). Always try swapping between FF and Chrome to see if there is any difference. Do this even if you had a poor experience in the past with a particular browser version. Things change all the time. BTW: FF sometimes exhibits slow performance with roll20 sheets with it's auto-fill enabled. IME, I've had a similar issue with Chrome and the Lastpass pw manager, so extensions can also cause conflicts.