Yongheng compressor filling slows down with oil/water separator

Hi to all the compressor owner out there! 

I recently installed the much recommended oil/water separator onto my Yongheng, and I noticed that the fill time increased significantly. To fill a 290cc gun from 130 bar to 250 it could be done within a minute. But now with the oil/water separator it takes almost 2 mins. And when you release the pressure when filling is finished, significantly larger volume of air is released from the compressor with the filter on.

Is it normal? You guys just endure the almost doubled filling time? Or I missed something here?



ps: this is the separator:

https://www.amazon.com/Diving-Seperator-compressor-Filter-L350mmOD49mmID36mm/dp/B07KQVC5SZ/ref=sr_1_8?dchild=1&keywords=yong+heng+Water+Oil+Separator&qid=1620718245&s=hi&sr=1-8
 
Yes it should take longer for the reason noted. I added a little more volume to my system with the install of a couple of Yong Heng filters. The first one keeps a good amount of moisture out of my desiccant filter to prolong it's life. I change it out every twenty minutes and let the old one set out to dry for reuse . Any moisture in the second one will tell me it's time to change the desiccant filter out.


 
I use this sieve in my second filter, it's easy to tell when it's exhausted as the blue beads go beige. I just remove the outlet side cap periodically. My small black filter from lethal air will typically go three months between media changes, but then it doesn't hold as much as the gold Tuxing does.https://www.ebay.com/itm/303197392846?hash=item4697f90fce:g:CDcAAOSwnDJbTL5F