Hi
Inventory_flag is intended to be used for Inventory command (code = 01h), not for read command.
For Read multiple blocks command (code =23h) in addressed mode (i.e. with UID parameter in the request), the Address_flag (bit 6) shall be set to 1. Usually Data_rate_flag (b2) is also set to 1 (High data rate shall be used):
b8 b7 b6 b5 b4 b3 b2 b1
0 0 1 0 0 0 1 0
0 Sub-carrier_flag: A single sub-carrier frequency shall be used by the VICC
1 Data_rate_flag: High data rate shall be used
0 Inventory_flag: Flags 5 to 8 meaning is according to table 4
0 Protocol Extension_flag: No protocol format extension
0 Select_flag
1 Address_flag Request is addressed. UID field is included
0 Option_flag
0 RFU
For further information on request flags, see ISO/IEC 15693-3.
See as well https://community.st.com/s/question/0D50X0000CBlUz2SQF/about-ios-13-extendedreadmultipleblocks-command for limitation on Extended Read Multiple Blocks.
Rgds
BT