Quick update: I did bypass of my big UPS, which is powering almost whole home, and clicking…disappeared! So I’m fool, I should do this much earlier and I was looking in a wrong place. Victrons are working like a charm. Problem is with UPS. Some of you already suggested that problem may be with load attached, but I was blinded with that source of clicking sound… 
I’m fool!
Apologize with bothering you all and have a great day!