Hello! This is quite unexpected, there should be no issue with using the same texture over two samplers, however it is usually recommended that you set your
Texture Sample nodes to Reference mode when you need to sample the same texture more than once in your graph, as per the example below:

Here's a practical example, taken from the node's wiki page:

Unfortunately, we haven't been able to replicate the issue you've reported on our side, so would it be possible for you to share both shader and material with us so? If you prefer to do so privately you can use our
[email protected] email to send the requested files, thanks!