Hi, first post here. Really need some help... Had a water leak and installed a new shower drain. All went well but floor pan is flexing and I'm really worried that the flexing is going to break the drain pipe, as its only 8 inches long or so from the p trap to the manifold. Shower pan was installed incorrectly as seen in the picture. There's no mortar under the pan. Of course this picture was taken before the new drain was installed. Does anybody know a fix for the missing mortar to stabilize the shower pan? I'd really appreciate it. Thanks in advance!