2003 volvo isx15 cm570 issues

[Magnat1976]

Hello,please advise asap..
We did mechanical compression test..
Cylinder#1-500
#2-520
#3-580
#4-600
#5-570
#6-580
Difference between #1 and #4 is 20%
Is it out of tolerance, critical?I have blow by,not huge,almost no oil consumption.
This can cause stumbling, surge,loss of power,and very bad vibration on road speed at 65mp.1500rpm..