I have seen this behavior for a while but never put two and two together.
i had seen that when labeling a cue sometimes while labeling the cue label doubles. but that second identical text always disappears before i press Enter so the doubled text doesn't make it into the resulting label.
last week i finally understood that it's happening when typing very quickly. it happens both when repeatedly hitting the same letter very quickly, and when keeping a letter pressed until it repeats. but it only happens when insertig a letter, not when appending a label.
seen in 3.2.5 on an Apex 10, but seen before.
thx, ueli