Unfortunately, investigators seldom give progress reports, we can only hope they're investigating the lead even if it appears stalled or not moving forward to us.
Sometimes a lot goes on/is going on behind the scenes and we're only made a ware of it if/when something breaks. In Marcia King's case, the potential match many of us had submitted since 2013 for Patricia Salamandyk looked like it fell on deaf ears, until one day she showed up as a rule out on Buckskin Girl's NamUs page. Though it appeared out of the blue (to me, at least), when I called and spoke to the detective on her case about the rule out, he confirmed for me it was done with DNA and it was years in the making, as in this case it took longer because they were working with international agencies.