Operating system: Darwin-18.7.0-x86_64-i386-64bit 64 Bits
Graphics card: AMD Radeon Pro Vega 64 OpenGL Engine ATI Technologies Inc. 4.1 ATI-2.11.21
Broken: version: 2.81 (sub 16), branch: master, commit date: 2019-11-05 18:23, hash: rB9d1031b01199
Short description of error
Click dragging vertically through the UVW parameters of a Lattice will let you select all 3 parameters (as expected).
But, entering a new number will only change the 1st of the 3 selected parameters.
Weirdly, click drag selecting all three parameters and entering nothing-at-all and then clicking away will somehow enter in the correct number that was entered one attempt back in time.
Exact steps for others to reproduce the error
Start a new General file and delete all objects.
Add a Lattice.
Go to the Lattice Properties.
Click and drag down through the U, V and W fields.
Enter a new number.
Notice that only 1 of the parameters changed (when all 3 should have changed).
Click and drag down through the U, V and W fields again.
Notice how the other 2 parameters "catch up" to the first 1.