Windows 10 / GTX1060
Broken: 2.81a, 2.82beta, 2.83alpha
short: 32bit displacement map seems to be clamped using displacement modifier. Works fine connected to shader nodes and rendered using Cycles.
long: We are working with displacement maps generated in Substance Painter. If exported in 16bit format, everything is fine. If we need more precision and exported the same to a 32bit format (tiff or exr), the displacement modifier renders strange clamps: every valley disappears and is not displaced at all, only the positive values are used. If you connect the same 32bit map to a Cycles material output node (displace on shader level), it is rendered fine.
Attached examples use the same texture, switch to rendered viewport in test_using_shader.blend .