As its in 3mg strength im guessing your not in the UK as max size with nic is 10ml here.
sounds a bit iffy as mothers milk should be ready to vape as i guess its been on the shelf in the shop so thats steeping.
Ive only had it happen 2 times in 10 years for me where i had strong chemical taste and after 3 months they were dumped as they were still rank. one was just cheap shite and the other turned out to be black market fake and that was around 9 years ago.