HI Henkjan, sorry this is a bit late but I too have experienced this issue on a Hudl Android tablet. Exactly as you describe, the more text elements on screen, the more flickering / non-appearing of the actual text. It does not appear to be caused by the scroll rects, I have observed non-rendering of text when removing the scroll rect from the parent object.
To test the issue I created a new project containing a single canvas with a scroll rect. The content child object had a child container with a vertical layout, stretching its children by width only. That container had 60 panels, each of which had one button with some text. I have experimented a little with some workarounds, none of which are entirely satisfactory. Here are my notes:
Build 1: approx 60 buttons inside content of a scroll rect, identical text of around 15 words on each button.
Result 1: Only a small number of the texts were displayed. As the scroll is performed, some flickering of text observed.
Build 2: Removed scroll rect.
Result 2: Only the bottom 4 buttons had their text showing. There were approximately 15 buttons visible on screen.
Build 3: Scrollrect re-added. Horizontal scrolling disabled, only vertical allowed.
Result 3: Problem remains.
Build 4: Moved scroll rect to empty child of canvas and put content as a child to that.
Result 4: Problem remains.
Build 5: Disable Android TV compat. All panels, buttons and texts set to “Static”.
Result 5: Problem remains.
Build 6: Returned relevant objects to non-static. Changed the text material to Sprites-Default (was ‘None’).
Result 6: Problem remains.
Build 7: Changed the Button’s Image material to Sprites-Default (was ‘None’) and set the image to fill center = false so that I might see through if the image is for some reason hiding text.
Result 7: Slight change, though largely similar problem. Now, I can see some broken text on some more of the buttons. For example, where before i would see:
blank
blank
this is some text
this is some text
this is some text
blank
blank
blank
this is some text
this is some text
this is some text
-----Now I am seeing extra broken text:
blank
ome text
this is some text
this is some text
this is some text
blank
blank
is some text
this is some text
this is some text
this is some text
Build 8: Changed the font to a custom font after reading that this helped for someone in Unity 4.3 when they had problems with text not showing.
Build 8: Problem remains.
Build 9: Added some custom script to each panel, detecting visibility and displaying text only when visible. Scripts have a string that saves the content of the constant text content in Start() and if the text is not within the camera view rect, the text is set to an empty string.
Result 9: Considerably improved, though a couple of buttons on screen are still missing text. More text is showing however.
Build 10: Alternating text this time, instead of each text being the same. Still using around 60 buttons.
Result 10: No change from previous.
Build 11: Added SetActive true/false statements to the panels to enable/disable the buttons and their text objects.
Build 11: Much improved, but there is still some text that does not appear at the top of the screen. About 90% is appearing now, as opposed to the original 15% or so.
Build 12: Half-sized strings. More (~70 total) buttons.
Result 12: Problem got worse. It seems that the problem is related to the number of text objects and not the number of characters.
Build 13: Added the custom font to Preloaded Assets array.
Result 13: No change.
If anyone else has experienced this, please contribute to this thread. This is perhaps a hardware issue on the devices concerned. I have not yet tested on other devices.
