Is offset of 30 in load and store instructions shows an exceptional case?

Hello to all,

I am working on ARM Cortex-M4 and the memory arrangement is the little endian. I have started working on the memory instructions and for that purpose, I have chosen the offset addressing and the relationship between the offset and cycles has been shown below.

According to the mentioned table for offset value of #0x30(in hex = #0x1E), the clock cycle consumption should be 2 but on observation, I have found that for from offset value = #0x30 the clock cycles consumption is 1.

Along with I have seen another observation that the all the offset values afterward, do not follow the similar order rather it was seen that the offset value of 31 takes 3 cycles, offset value of 32 takes 2 cycles, offset value of 33 takes 3 cycles, from 34 it again starts with the cycle of 1. For better understanding I have shown a table below:

Can anybody help me with this, why such strange behavior from the offset of 30 onwards (in case of both load and store instructions)??

Kindly help me out with this.

Thanking you,

Kind Regards,

Himanshu