I also did some speed tests regarding these LTE band frequencies. Btw I'm a Globe user and my area is around Northern Luzon (Region 3).
Findings:
Band 3 → 10.2mbps (low ping)
Band 28 → 1.1mbps (slowest)
Band 38 → 1.2mbps (almost no diff with 28)
Band 40 → 7.8mbps (stable ping)
Band 41 → 5.1mbps (decent)
Conclusion:
I've been struggling with my ping lately while playing Mobile Legends where I always experienced sudden ping strikes resulting to delays and ofcourse defeat. This ping issue arouse after the announcement of ECQ (enhanced community quarantine) since more people are at home browsing and have nothing else to do. So I tried locking my device to LTE Band 3 and after a month of suffering, finally ML is already playable. Thanks everyone for the tips.