I've called many moose but even a few days prior to pre-rut [9/10] are unproductive.
During pre-rut and rut, bulls often don't respond well on warm days or to an area where they may have to
exert themselves....uphill.
You can get a curious young male to follow sometimes.
One spring when hiking I called in a bull to 10 yds then couldn't scare it away. We backed down the trail and got around the corner then jogged for 1 km then hiked another 1 km and sat down for a drink and snack. My friend was afraid of moose and it was great. Next thing we know the moose is sauntering down the trail and is only 50 yds away. Felt like a horror movie LOL. My friend almost crapped himself.