Serial Monitor causes 100% cpu load after device is disconnected

[bitluni]

Windows 10 Pro, XPS 13 Core i7
When the Serial Monitor is open and the device that was connected at the configured port is removed the Serial Monitor takes a core to 100% load. That is quite annoying on laptops especially when the moitor is somewhere in the background not being noticed.
I have this issue since ever on different versions. My current is 1.8.8

[per1234]

Closing as duplicate of #2333

This should be fixed by #8046

Other reports:

• 1.8.5 / high CPU load #7505 (comment)
• High CPU load - Bug of code editor? #8009 (comment)
• High CPU load - Bug of code editor? #8009 (comment)

Please test with the Beta Build of the Arduino IDE to see if #8046 fixes the problem for you:
https://www.arduino.cc/en/Main/Software#beta