Regression: Can't debug "this" variable in class that exists in a separate thread

I recently updated to Qt Creator 4.3.0, and when debugging an existing project, when I set a breakpoint in a class that runs in a separate thread from the UI thread, I'm unable to debug the "this" variable when the debugger breaks. This behavior worked with the same project in Qt Creator 4.2.1. I've attached some files that show the problem:

• breakpointHit_4_2_1.png - shows what I see in Qt Creator 4.2.1 when the breakpoint is hit
• thisExpanded_4_2_1.png - shows what I see in Qt Creator 4.2.1 after expanding the "this" variable. I'm able to see all the member variables of this class
• breakpointHit_4_3_0.png - shows what I see in Qt Creator 4.3.0 when the same breakpoint is hit, which shows that "this" has a valid address of 0x326f41f0
• thisExpanded_4_3_0.png - shows what I see in Qt Creator 4.3.0 after expanding the "this" variable. I'm not able to see any of the member variables of the "this" object, and the address has suddenly changed to <not accessible>

My actual application functions properly when run in either version of Qt Creator, I just can't debug it properly.

I think the fact that the class lives in a separate thread might have something to do with the issue. If I set a breakpoint in mainwindow.cpp for example, I am able to expand the "this" variable using either version of Qt Creator and debug member variables of the MainWindow class. But when I set a breakpoint in the class that is running in a separate thread, I'm unable to expand that class' "this" variable and take a look at the member variables when running Qt Creator 4.3.0. Under Qt Creator 4.2.1 it works fine