There is some new type of music called lofi which are slow relaxing beats that are usually used for concentration/sleeping/relaxing/late night drives or even just chilling etc. Is this considered to be haram music of entertainment?

There are different types of lofi music. Some of it which is purely classical and not typical or entertainment music is permissible. However, some of it may be typical of some entertainment beats/tones, so it should be avoided. Only listen to the ones you are sure are classical and not usually found in entertainment gatherings.