explore mode fails when switching between modalities

[LTLA]

If you have a multi-modal analysis

AND you switch between modalities in the UI

AND the row data is different between the modalities,

we see the following bug:

I've traced this to

kana/src/components/Markers/index.js

Lines 1154 to 1156 in e6764a7

	genesInfo[geneColSel[props?.selectedModality]][
	row.gene
	]

where it seems that geneColSel[props?.selectedModality] refers to a column of genesInfo that does not yet exist because genesInfo is still pointing to the previous modality's row data while geneColSel[props?.selectedModality] is new.

I think this is because geneColSel remembers its previous selection (which is good), so when you go to a new modality and then go back to the previous modality, it tries to retrieve the previous selection (so far so good) but the genesInfo has not yet updated. I guess there must be some code that defends against this on the first selection of a new modality, but this is skipped when we re-select a modality that we went to before?