What’s the bug?
ramli7 found out that in Micromax MMX 300 C EVDO modem, if you set HSIA-only mode, it will display HSIA signal but the connection will be in CDMA 1X speed only [ in windows network connections - it will show as 153.6 Kbps (144kbps in theory) ]
How to fix?
Head over here and read the thread to know how to resolve this bug.
Finally, I thank ramli7 for finding a workaround to fix this bug and helping others.