[Python] GNU Radio + RFNoC FIR Filter: Block connections remain red despite matching types...

I'm working on a GNU Radio Companion (GRC) project that uses two USRP X410s. The goal is to use one as a transmitter/receiver and the other as a channel emulator running a FIR filter on the FPGA via RFNoC.

In the flowgraph:

The USRP Source outputs complex float32.

I use a Complex to Float block to split the stream.

I feed the real and imaginary parts into separate RFNoC FIR Filter blocks (configured for float taps).

Then, I recombine them using Float to Complex, followed by a USRP Sink.

Problem: Despite matching data types (float32), the connections to the FIR filter blocks remain red and cannot be validated or executed. I’ve ensured:

Tap values are within [-1.0, 1.0] and provided using .txt files.

FIR blocks are configured for float coefficients.

A RFNoC Graph block (Device) is present in the graph.

Has anyone faced this issue before or knows what might be missing?

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