Blight towers still not buildable or upgradeable (occasionally)

Sometimes - about 5% of the time... there will be one slot or maybe two at a push that won't allow building any towers, or a tower that won't allow the upgrade button to be clicked.

In the second instance (trying to upgrade) I'm finding the character simply runs up to the tower instead of the upgrade being processed.

Several threads from the past year or so seem to point to this but have been "archived". PLEASE devs... try to fix this!

Thank you :)