You cannot overwinter a Japanese maple indoors under living conditions comfortable to you. Bringing it inside pushed it out of its required dormancy and into its regular warm season growth mode.

If it is too cold to remain outside over winter, then it needs to be moved into a protected location but one that stays above freezing but below 45F. Something like an unheated greenhouse, insulated shed or unheated but attached garage. Or depending on your location/hardiness zone, you could dig a hole and bury the container. You just cannot treat it like a houseplant...it is NOT!

Where are you located? It should be outside. not an indoor tropical plant.

I'm wondering if "northernbc" denotes Northern British Columbia?

Don't keep cutting it off!

Get it into a colder location.

You don't want it to freeze.

An unheated, north facing porch that doesn't freeze at night would be good as long as it doesn't get above low 40's during the day.

As mentioned, deciduous trees need a cold dormant period during winter.

" It should be outside. not an indoor tropical plant "

Due to their compact size, many people grow Japanese maples in containers. This is also common in areas that may be too cold to grow JM's in the ground safely. And containerized JM's can be vulnerable to winter cold damage even in very mild winter climates. Moving to a protected but cold environment is SOP.

Thanks for all the responses. i will place it in my garage that doesnt freeze but stays cooler. i understand i should avoiding removing new growth and try to keep cool for winter. Thanks

And yes northern British Columbia