Question: Could possibly (still) be a bug? Rank of a symbolic matrix

I am a research student and I am writing up my thesis. I was reading one of the paper written earlier by authors in 2003.

The authors calculated a symbolic rank of a matrix A, and got 9, using Maple 6.

Then new methods developed in 2012 and proved that the "true" rank should be 8. The later paper that "Most  recent versions of Maple have this simplification built in and are able to return a rank of 8.".

I just noticed that in Maple 18.01, this matrix was still evaluted for a symbolic rank 9, if no simplifcaiton was done before using Rank(), see attached.

I didnt explore a lot, but just as a notice. I am a bit concerned as most of my research was trying to deal with exponentials.

Is that something to be fixed in future versions?

Thanks!

 Bug.mw