Since updating to Photoshop CC 2015.5, I have encountered many challenges in having text appear properly for me. Characters in a text layer will disappear and reappear on a whim and there's nothing that I've been able to troubleshoot that has helped.
Bounding box is not an issue, as this happens as this will happen no only the LAST characters, but the FIRST characters of a text layer. Usually if the bounding box is not big enough, the whole word will disappear, not just one or two characters.
The example below is created as Point Text, not a Paragraph Text, so there aren't any bounding boxes.
This problem doesn't appear to discriminate between fonts. The screenshots above is your plain ol' Helvetica. Fonts that never had an issue in a past version of PS now have this issue. Some don't.
When I hit the down arrow on the current font selected and roll over the different fonts installed on my computer (which gives a live preview of what the font looks like on my canvas), it will flip back and forth between showing the character and not, depending on what font is selected.
The problem is really inconsistent. I've had the "H" in "Hello World" both appear, and then disappear again on its own whim (while playing around switching between a font that works properly and back to one that didn't before).
Here's the font "Close" selected... Umm... a different word disappeared all together?!
Even this functionality in itself is inconsistent when it shows up (never sure what triggers the marquee underline; how to get the underline back; underline disappears when you select a different font; underline doesn't show up again when you select the same font as before, etc, etc)... but that is another issue all together...
Anyway, I could probably play around with this all day and it would do crazy stuff in all different ways. Hopefully this can be fixed and that this is helpful for you folks troubleshooting.
For now, I'm going to try to revert back to the previous release 😞