The threads on both ends of a Tuxing filter are M10*1 metric threaded and require the white delrin disk in the bottom of the filter to seal. It is a parallel threaded fitting so no teflon tape is needed to seal it. It seems that a lot of the male fosters from China are slightly out of spec. I've found that on a lot of the male fosters the length of the middle bulged section seems to be a little bit too long. This doesn't allow the male foster to go far enough into the quick connect to allow the ball bearings to snap over it.
Sometimes you just have to mix and match fittings that should work together but don't. I haven't had any male fosters that were too wide to enter the quick disconnect like Mwerks experienced. Unfortunately for James.Revels the parts he has should connect to each other. Most of the time it is the male foster that is the culprit since some are out of spec.
James.Revels should first see if his male foster enters the quick connect fitting. If it does enter the quick connect then don't spin it to reduce the width of the male foster. If it enters the quick connect bu won't snap on, carefully sand the tip of the male foster flat against sandpaper to take a few thousandths of length off. This will allow it to go deeper into the quick connect and seat it. Finally, if that doesn't work, be sure to replace the male foster with one that has M10*! parallel threads otherwise it doesn't properly seal onto the Gold Tuxing filter. You can substitute a 1/8 NPT threaded male foster which is tapered and will seal with teflon tape, but it isn't the correct size for the filter. Male foster fittings are easy to find and inexpensive from Aliexpress.com but it takes a month or longer to get them shipped from China.