Weighted averaging

[thetalladam]

Hey, sorry for the lack of context but I am studying diatoms and trying to use the weighted averaging wa() function in analogue and am running into an issue of differing results.
The first image is a caterpillar plot using the optima() function. The second image is a caterpillar plot of the same data but using the wa() function. I wasn't sure if the transfer function model aspect of the wa() function was affecting the results. Eventually I performed the weighted averaging in Excel to verify and found the wa() function was similar, but not exactly the same. Could someone describe the potential differences in calculation between these functions?

Interestingly, using the Imbriekipp dataset for resulted in the same graph for both functions. Could the problem lie in my dataset?