This issue isn't necessarily with the CnCNet launcher / dlls / ddraw compatibility layers etc. because it happens with the vanilla game also, I've had it for many years, but I've been advised to post here in case it can be fixed or anyone has any solutions.
Normally: with Tooltips enabled (either in-game, in the CnCNet launcher, or with ToolTips=yes in the .INI configs) hovering over a structure or a unit with the mouse cursor for a second, will reveal the structure/unit name as a pop-up which will remain displayed until the mouse is moved away.
However, in my case, this does not happen: the tooltip never appears, or when it does appear, it appears on screen for a single sporadic frame and immediately disappears. The time it takes for this to happen is inconsistent, but even this is rare - sometimes after 4-5 seconds, sometimes never, sometimes repeatedly.
What has no impact:
- different renderers (cnc-ddraw, ts-ddraw, DxWnd, DDrawCompat etc.)
- different subsystems (opengl, direct3d9, gdi etc.)
- display mode (windowed, fullscreen, borderless etc.)
- Back Buffer in Video Memory
- different versions of CnCNet client/launcher/dlls
- running with vanilla gamemd
- Windows compatibility modes in the executables
What has some impact:
If the game is set as borderless window and hook_peekmessage=true is enabled, when the cursor is left over a unit and Start or Alt+Tab is pressed the game will unfocus but will keep running with the ingame cursor still in position, and the tooltip appears. This leads me to think that something related to the message handling is afoul, like mouse events spamming the internal timers.

