Problems with Bulldoze

[CityBuilderPie 37]

Started playing again; some DLC went on sale as well as a few content packs, so I treated myself and got back into it.

Added Natural Disasters to my game and updated my mods. Got rid of a lot of content I wasn't really using. Game is pretty smooth and I have encountered decent load times, stable cities, etc.
Only one thing:
I cannot bulldoze underground (tunnels). I can build underground, hitting Page Down key is fine. I can bulldoze on ground level and all levels above ground, I use the B key for bulldoze and Page Up for levels above ground.
But when I page down, either hitting B or clicking the onscreen bulldozer icon pops me back up to ground level. 
When I try it the other way around, hit B or click the bulldozer icon, I get the bulldozer fine and it works fine, but I cannot Page Down (unless I deactivate bulldoze).
Anyone else have issues with deleting tunnels recently? How did you solve it?
 

[Horus_Kol 118]

Underground bulldozing seems to be fine for me - I play a pretty vanilla game, though (DLC and that's about it).

[.Del 53]

There is now a button called Toggle Underground Bulldozing. It was added during the 1.7 update.

[Avanya 2,605]

Picture thanks to Pres - also I think the shortcut is V