Some texts become blurred when multiple tabs are opened in a window

• I am on the latest Hyper.app version
• I have searched the issues of this repo and believe that this is not a duplicate

• OS version and name: Ubuntu 18.04.2 LTS
• Hyper.app version: 3.0.2
• Link of a Gist with the contents of your .hyper.js:
• Relevant information from devtools (CMD+ALT+I on macOS, CTRL+SHIFT+I elsewhere):
• The issue is reproducible in vanilla Hyper.app: Not sure. I will try it later.

Issue

When working under Ubuntu Desktop 18.04.2 with default desktop environment (I didn't encounter this issue in macOS or Windows), some texts in the middle lines in a window (top and bottom lines look well) become blurred, if I open multiple tabs in a window. A window with single tab is working well.

If I close other tabs to leave it a single tab there, the text rendering becomes sharp again.

A pair of screenshots are attached here for comparison (look at the line of 'yes')

Below is the screenshot of "blurred texts with multiple tabs"

Below is the screenshot of "clear and sharp texts in a single tab"

If you need more information, please ping me.
Thanks in advance.

Start by reproducing the rendering problem in Hyper.app 3.0.2 on Ubuntu 18.04.2, comparing one tab with multiple tabs and checking the supplied screenshots. Use the relevant devtools entry point mentioned in the report, then determine whether the text remains sharp with multiple tabs in a corrected build; the report does not name a file or test.