Welcome to the forum.
If the water IS from the overflow lines, the next step might be verifying how much water really is in the tanks. Most tank gauges in RVs aren't always accurate.
Sherm & Terry w/rescues Steve (std Poodle) & Eydie (min Schnauzer)
2015 Jay Flight 27RLS (Camped: 102 nights 2015, 90 nights 2016)
2006 Ford F350 6.0 PSD, Lariat, 4WD, CC, LB, SRW, auto., Camper pkg.