So, most Fiber ISPs in Malaysia borrow/rent TM's Fiber infrastructure
Basically the fiber cables from your home to the node
Once it reaches there it splits off to your ISP
Instead of every isp running cables to your home, TM does and others rent it
This has some benefits but also some downsides like all the pricing being fixed, like how everyone offered RM89 30Mbps in the past
This is refered to as Maxis on TM Infra

In some rare instances, Maxis will run its own cable instead of using TM's. This is usually for high rise, or new areas where they got in quicker than TM
This is refered to as Maxis on Maxis Infra

Usually, Maxis will offer special promo prices that are far cheaper to those on Maxis own infra as they own the cable and don't have to pay TM, so, their costs are reduced.

Other ISPs that run their own infra are TIME and TNB Allo
But both of their infra could be used by other isps too (such as Digi)

If your LAN cable is connected from LAN2 of the modem to the router, TM
If it's LAN1, Maxis

Or in the UI
check the VLAN ID of eInternet
621 for TM, 11 for Maxis