Choosing "Nodes" as the unit seems to still select a region in units of sequence length

[jeizenga]

For example, this does not look like 100 nodes:

[wolfib]

I have noticed some strange behavior regarding the length of the displayed sequence too.

Does unselecting the "remove redundant nodes" checkbox in the visualization options make any difference in your specific case?

Tubemaps itself does not manipulate the sequence. It just passes the parameters on to vg and then shows whatever vg returns. So it seems that it either does not use vg's command line options correctly when calling vg or that vg does not always handle these parameters as we would expect.