Describe the bug
If the title of the post in Gutenberg is long and it has 2 lines, then only one line is displayed sometimes
To reproduce
Steps to reproduce the behavior:
Expected behavior
So see the full title not only half the title
Screenshots
Screenshot what I see ----------------------------->

Screenshot what I expected to see ----------------------------->

Desktop (please complete the following information):
Additional context
Gutenberg version is 6.4.0 and so many bugs, it should be BETA 0.6.4.0
@u1qqlv Thanks for creating this issue. I haven't been able to reproduce it despite a number of attempts, but I'll keep it open just to see if there are any more reports.
Please could you avoid posting additional commentary like "Gutenberg is a disaster". Those kind of comments belong in a blog post. This is an open-source project and it's important that every contributor is made to feel welcome.
I've been seeing this mistake for a long time. It can be reproduced. This does not always happen, so I can assume that it is related to incorrect calculation of the height element in post-title component.

Оn the example above, on the third attempt, he showed everything normal. Try the long headings of 4-5 lines.
Some updates:
I'm using clear Wordpress 5.2.2
I think the bug due to this component:
Apparently he doesn't always have time to calculate the altitude correctly.
Thanks for the extra details. I wasn't able to reproduce it with twentynineteen as the theme. I switched to the Gutenberg Starter Theme (https://github.com/WordPress/gutenberg-starter-theme) and it was easy to reproduce with that.
You're welcome! I will try to find more possible reasons - maybe it's because of the delay in drawing fonts? twentynineteen uses system fonts (minimum delays load), but Gutenberg starter theme and mine - Noto from Google Fonts.
Some updates:
@talldan try installing a Twenty Seventeen theme, which also uses fonts from Google Fonts and reproduce a bug. I did it. But with four attempts.

Perhaps this is how it works - when page initialize, React Autosize Textarea calculates the height of the block based on the standard system font, then the font is loaded - but since it has different line spacing, letter height and other subtleties - we have this problem. Is there anything we can do about it? In React Autosize Textarea has an async option, but I'm not sure it'll help.
Yep, I think you're right, it probably is the async loading of fonts that causes it. When the bug occurs if I then set font-family: auto; in the dev tools the text fits perfectly.
I just saw it happen w/ the o2 Breathe theme, which also uses Noto Serif. Setting font-family:auto fixed it there too.
so is there a patch? / was this fixed?
If yes then we can close this...
@iandunn and @talldan is this a theme issue or is this something we can get fixed directly in Gutenberg?
I have myself come across the same problem a few times with different themes.
It seems like a bug in Gutenberg to me, and the intersection w/ fonts is just a symptom of the underlying problem.
Unless truncating the title is an intentional design decision, then I think it should be displayed in full, regardless of any CSS the theme sets.
Yes, I do I agree with you Ian!
I believe @ellatrix Ella has been working on something similar to this before.
Perhaps she is available to take a closer look at this problem.
Most helpful comment
@u1qqlv Thanks for creating this issue. I haven't been able to reproduce it despite a number of attempts, but I'll keep it open just to see if there are any more reports.
Please could you avoid posting additional commentary like "Gutenberg is a disaster". Those kind of comments belong in a blog post. This is an open-source project and it's important that every contributor is made to feel welcome.