The relative locations (upper right etc) of the terminals on the switch are not the factor with which you should be concerned. You need to know which terminal is the common. That gets the AC from the circuit breaker. The other two go to the loads. Are they marked? Do you have an ohm meter?
OK, based on your comment I think I know what's happened.
Your old switch appeared to you to have three terminals, but most likely it really had four, but two of them are connected together - maybe internally, hidden from you, or perhaps simply unnoticed? The new switch probably has an external shorting strap/bar - the RED in the pic below - connecting the two commons together.
The switches you've been using are both set up as a pair of single-pole single-throw switches.
Previously you had the AC coming in on the Common terminal(s) and the two loads (fan and light) each getting one of the Load terminals. That worked as desired.
When you replaced the switch, you wired the AC coming in to one of the terminals on the Load side (A1 or B1), and wired your loads to a Common terminal. Since the common side is shorted together, when you turned on the one switch to which you wired the AC input power, both loads powered up. The other switch is effectively non-functional.