MKDocs Colspan in Table

Question

I am trying to use colspan in a table in mkdocs

When I set the table up, with the same about of cells per row in the row that has the colspan, the table renders, but I have empty cells to the right:

|                         |   |       |  Version  {: colspan=5} |       |       |       |
|-------------------------|---|-------|:-----------------------:|:-----:|:-----:|:-----:|
| **TITLE** {: rowspan=5} |   | **E** | **F**                   | **G** | **H** | **I** |
                          | A | X     | X                       |       |       |       |
                          | B | X     | X                       | X     |       |       |
                          | C |       |                         | X     | X     | X     |
                          | D |       |                         | X     | X     | X     |

result:

If I remove the cells that should be filled using the colspan, the table doesn't render at all (I have to post a screenshot of the code because it gets half rendered as a table):

result:

Any suggestions as to how I can get teh colspan option to work correctly would be greatly appreciated. TIA