Context Menu pops up in random positions

[bog]

I built content_shell based on Chromium 54.0.2840.100 using ozone-wayland platform. The problem I have is the Context Menu pops up randomly on the screen even mouse right-clicks on the same position. I debug the code and see the (x,y) is correct from the mouse here: https://chromium.googlesource.com/experimental/chromium/src/+/54.0.2840.100/content/shell/browser/shell_web_contents_view_delegate_views.cc#75

however, I don't know which part I should take a look at. Can anybody give me some suggestions?

BTW, this is an ARM based embedded system and GPU is PowerVR SGX 425. The driver is a little old, as well as Wayland (1.6) and Weston (1.6). Thanks!