(1) You are using a resolution that's too high, given the number of parameters in play. Try reducing resolution (see
Interpreting Results for a detailed explanation).
(2) If you are already using "low" resolution, then these tubes are may
be from different samples (i.e different patients) and so the
distributions are very different. Remember, QTube is a QC tool to
make sure that multiple tubes from
a single sample are internally
self-consistent. Including multiple samples will generally yield
confusing (and probably meaningless) results.
(3) Even though your tubes all share a subset of common parameters
(often used to gate an entire panel), there may be a reason why these
distributions differ. We've seen for example in some Leukemia
panels that some of the tubes have been permeablized. This
significantly effects the distribution of events in the FSC, SSC and
CD45 gating parameters. In such a case it may make sense to QC
the the permeablized and non-permeablized tubes in two separate QTube
runs.