I am trying to produce a map with some fairly complex labels. The labels are built to look like this when ArcGIS pro doesn't crash:

This is built from 3 different fields using a python expression:
<SPAN class="string token">"<BOL><UND>{}</UND></BOL>; - {}; - {}"</SPAN><SPAN class="punctuation token">.</SPAN>format<SPAN class="punctuation token">(</SPAN> <SPAN class="punctuation token">[</SPAN>NAME<SPAN class="punctuation token">]</SPAN> <SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">[</SPAN>PROJECT_LOCATION_<SPAN class="punctuation token">]</SPAN> <SPAN class="punctuation token">,</SPAN> <SPAN class="punctuation token">[</SPAN>PROJECT_DESCRIPTION<SPAN class="punctuation token">]</SPAN> <SPAN class="punctuation token">)</SPAN><SPAN class="line-numbers-rows"><SPAN></SPAN></SPAN>I have set the label to have stacking:

As you can see from the screenshots, Pro does run and label correctly, but as soon as I try to pan the map a few times, or put the map into a layout, I get a crash. Sometimes the crash reporter pops up and sometimes it does not and instead Windows asks if I would like to restart the program.
I'm running Pro 1.3.0 on Windows 7 x64 with a fairly beefy machine and graphics card, so I don't think its the system.
Is Pro not stable enough for this type of labeling yet? Has anyone had any similar issues?