Both blocks setting and format of text are sharing the same databse field options in resource table. The problem is that when blocks are used, showblocks value overrides moodle format and the text is then treated as MOODLE_FORMAT
1/ remove format of text from Resource-Text, markdown is not used much so I guess it should not be a problem.
2/ use comma separated array to store both values in options
Waiting for response from MartinD...