@George I have even tried to reduce from two parameters to one so that I can be sure that the + operation was not causing some strange result, but this has made no difference.
video2
Replicating the original query in MS SQL using the two parameters will retrieve a record.
Potential workaround: have you tried performing the concatenation inside a set-value action step just prior to the custom query step, then just having one param to the query referencing the set-value step? This will rule out the concatenator somehow formatting poorly.
For troubleshooting, I would try a value that does not include special characters. I ran into that problem once, and Wappler was able to fix once identified.
I checked the projects not yet updated to version 5.4.0 and I noticed that the files generated with previous versions included in the query the output type “outputType”: “array”, while now it is omitted.
Maybe a very small bug.