That seems to have fixed the problem for me too. Thanks!

I just installed the latest update to inDesign 2018 (March 2018 - 13.1 I believe?) and now when I overtype existing text, the first character disappears. It seems to happen when typing over words in the middle of a paragraph. Overtyping at the beginning of a paragraph works fine. Very frustrating to have to keep checking to make sure I'm not losing characters.

Thanks it is now fixed!!!

That fix has worked for me too.

To remove double spaces from a paragraph of text you could previously highlight the double space and the hit the space bar once to remove it making it a single space.

Now you have to hit the space bar twice since the 13.1 update.

It's also the same when trying to replace a word, previously you could highlight the whole word and start typing the new word in it's place. Now you have to press the first letter key twice for it to start overwriting.

That resolved the issue for me too. Thank you!

ID CC 2108 13.1 (updated today)
When highlighting type in pre-existing text to type new text the first letter does not type, the rest of the word will type, but the first letter of the word has to be typed twice.

This worked! Thank you

That resolved the issue for me as well. Thank you!

The above suggestion resolved my issue as well. Don't know what that changes, but it fixes the two keystroke problem.

This resolves my issue...

Same issue. Trying to make some quick edits. Basic highlight a number and then press a new number to replace EXCEPT when I do this it doesn't "take" unless I press the key again. Only happens on single digit/numeral replacements, doesn't matter how much I highlight.

After update to 13.1, when I highlight a number with my mouse, I have to press a key twice in order for it to change to what I want. Huge inconvenience. I have Windows 10.

Very similar to me. Updated to 13.1 today and when highlighting existing text in a frame to edit, I have to press the key twice. Giant pain in the butt and creating all sorts of errors in my document.

Updated to 13.1 x64 today. Now when I highlight text in a text box to edit the text, it requires two keystrokes to achieve what use to be one. Existing text:
1/6 x 6/8 or something like that. I want to modify 1/6 to 2/0. I highlight 1/6 and type. The first time I hit the 2, nothing happens. Then I hit 2 a second time and it registers. This happens with any key.

Please let me know. Did not do this yesterday before I updated. Again inDesign 13.1 x64 on Windows 10 Pro

After update 13.1. When I type I have to do it twice before the character appears in the frame. I have windows 7.