MPR + Vaadin 7 IE looks different between production and dev mode jetty

Flow
1

Hello,
Why does IE look so different for the same code when running jetty in Eclipse debug. Of special interest is that, for production mode, the top is cut off. See screen shots below. I am running MPR + Vaadin 7, using a legacy custom theme via @MprTheme. Also, the header section is in the top panel of a VerticalSplitPanel. I only have this problem in IE, Chrome consistently looks good. Any ideas?

![dev mode jetty]
(https://i.postimg.cc/L6Lf8CWh/jettydevmode-IE.png)

Figure 1: Dev mode ( mvn jetty:run ), good header at top

![production mode jetty]
(https://i.postimg.cc/4xwYYrQ4/jettyprodmode-IE.png)

Figure 2: production mode ( mvn jetty:run-exploded -Pproduction ), missing header at top

2

Update after testing with Vaadin 14 RC3: Same thing happens there.

Just strange that “production” mode would introduce such changes.

I actually think it has something to do with using Vaadin 7 SplitVerticalPanel. I think if I just do something with “VerticalLayout”, it will work ( I tried this in a separate branch and it worked ). Don’t know if that helps answer the question.