I am also on lantus and novo rapid .
I would check the night time bm and see what is happening , then adjust .
If this doesn't work , and your bms do not come down . Then maybe you will have to talk to your diabetes care team .
I had a problem like this , and it was that my lantus wasn't making that last stretch of working time like it should of been , and was told to split my doses . So I have lantus in the morning and at night . But I'm not suggesting to do this yourself as you will need to talk to your diabetes team or doctor .
I'm just saying what I was told to do and it did sort things out as I had tried everything else .
Hope this helped .