ANT+ and Bluetooth Heart Rate Monitor

in Road general
I used to use just an ANT+ monitor and the battery would last 6 months or so. I've just switched to an ANT+ and Bluetooth combined and I've found the battery only lasts a month (I have 2 and both are the same) Is this normal?
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2020 Voodoo Marasa
2017 Cube Attain GTC Pro Disc 2016
2016 Voodoo Wazoo
Fun: Yeti SB66
Road: Litespeed C1, Cannondale Supersix Evo, Cervelo R5
Trainer: Bianchi via Nirone
Hack: GT hardtail with Schwalbe City Jets