GIMP-2.99, small screen, top and bottom arrows of the layer blend menu disappear
On Debian Sid, using IceWM and GIMP-2.99 in Multi Window Mode on a small screen (1600px by 900 px), as shown by the screenshot below, the layer blend drop-down menu dialog doesn't show arrows at top and bottom, which makes it impossible to select the LCH blend modes:
After starting GIMP-2.99 the top and bottom arrows are actually shown the first time the layer drop-down menu is accessed, but not the second time.
Switching to another layer mode using default vs legacy button and then back again brings the top and bottom arrows back, but only for one additional try at changing the layer mode using the drop-down menu.
Likewise using the Layer Attributes dialog allows to change the layer blend mode, and in turn allows one more (only one more) chance to change the layer blend mode using the layer blend mode dropdown menu. At which point to make an additional change to an "offscreen" layer mode using the layer drop-down menu, again the user must either access the default vs legacy button or else the Layer Attributes dialog.