What is the triangle components in this diagram?
Those triangles are simple buffers to drive the MOSFET gates, and they can be disabled by pulling OE low. Think of them as the same as (SN)74LVC1G126 buffers.

But the edge accelerators are not important.
For a low signal level, the FXMA2102 connects both buses together. This means that all pull-up resistors on all buses are connected in parallel. So when each module has its own pull-up resistors, each module increases the current that the driving I²C device must sink.

In a properly designed circuit, you should have only a single pull-up resistor per signal line. When using modules, don't add another pair of pull-ups at the master, and consider desoldering them from all but one module.