Blank EXCALIBUR in summary table (over half a year old bug)

[Turbo_Trotldyt_R-Zone_64]

For over half a year I keep seeing this blank EXCALIBUR in my summary table. Today is an exceptional day: it has multiplied to 2. I don't own a regular EXCALIBUR btw. It appears about 80% of the time. The screen below is after finishing today's Sortie mission #3 (Rescue on Taveuni). Notice that both have black picture, same rank and white dot above and below rank line.