Driver capability issue with the PMOD port

Hello everyone! I'm currently facing an issue with the insufficient driver capability of the PMOD port. I've built an SPI IP using Vivado and connected it following

It runs fine in Jupyter.
My goal is to drive an Intan RHS2116 chip to obtain its internal register values.
However, when I connect the chip using jumper wires, the originally normal signals become weak. I captured two types of signals with an oscilloscope.
In Figure 1, without connecting the RHS chip, the outputs of MOSI and SCK are somewhat normal. But when I connect the RHS, the signals turn into Figure 2, and everything stops working properly.
Can anyone help me out?
Figure 3 shows the pinout for the RHS chip. Thanks.