Welcome to the forum. We have a list of suggestions here for answering questions. Well done on finding out how to post code correctly.
The other big thing in How to get the best from this from this Forum is that posting a snippet of code is not much use. So often the code that contains an error is not in the place you think it is.
It also allows us to try your code ourselves.
I would say no. It is more likely to be an output voltage thing. The fact that you have other 3V3 devices driving the circuit correctly is beside the point.
No 3V3 device has sufficient voltage output to drive a 5V powered input, it is just that the some might work because they are supplying enough voltage to "just" make it function. Your Nano Every might very well be within its specified output voltage range but is slightly lower.
That suggests to me that the "fanout" capability of the Nano Every is quite poor, probably caused by the poor output impedance and while it can supply enough signal to drive one load, supplying two loads is tipping it over the edge.
I would suggest you buffer the output with two of the inverting buffers of a 74HCT14 in seriese to boost you signal.