Due to a problem in the Quartus® Prime software, the bit[8] of "Device Control register (0x088)" is never set to "1" even if the Number of Tags supported in the Capabilities Registers tab is set to "64".
Also, the user cannot set it to "1" by Configuration Write Request.
The <Qsys file>/synthesis/<Qsys file>.v contains the parameters below:
Changing these two parameters to "1" and "true" should fix the problem.
[Before]
.extended_tag_support_hwtcl (0),
.extend_tag_field ("false"),
[After]
.extended_tag_support_hwtcl (1),
.extend_tag_field ("true"),
This problem is fixed starting with the Intel® Quartus® Prime Pro Edition Software version 18.1.