Lifts, balancers, and sorters are too sensitive to terrain height

Both basic transports (conveyors, pipes, molten channels) and buildings are fairly forgiving as far as the height of terrain they can be placed on. It will be flattened for free to a certain extent.

Items in the Transports tab other than the transports themselves give zero such leeway. Here's an instance where the terrain is flat enough to show the grid (so you wouldn't even think that it wasn't perfectly flat) but you can't place a lift (or balancer or sorter). (I made a loop of belt around it to further illustrate the point.)

will it place if you press e once?

Yes, but it wouldn't connect to a 0-height belt in that case (or to the port on any machine/storage).

Was that a “copy/paste” lift, or a new one from the transport menu?

The way to deal with what I think you have there is to set the input at the output height and the output at the desired input height, then click the “reverse direction” button in the lift’s dialog box.

If you click the lift in the transport menu, it should default to a level 0 to 1 lift, while copying one gets you the exact layout you copied, and can only change directions and height above ground without adjusting the difference in height between input and output.

The direction and height-span of the lift are irrelevant. (The screenshot is the first step of placing a new lift, btw.) And I believe I mentioned that the problem occurs for sorters and balancers as well.

I had reported a more specific case in Canary early April. Yes, should really get fixed/improved.
https://discord.com/channels/803508556325584926/1224519903541989418