I tried this:
ax = Axis(
f[1, 1],
xautolimitmargin = (0, 0),
yautolimitmargin = (0, 0),
title = str,
xlabel = "Channels",
ylabel = "Index of event variable",
xpanlock = true,
ypanlock = true,
xzoomlock = true,
yzoomlock = true,
xrectzoom = false,
yrectzoom = false,
)
There is an effect, but you need to find correct axis!