I have a problem which I cannot resolve on my own, after already trying some things. I am working with the prof. license and I have a reflective construct with four indicators. In SPSS and with the PLSc I get wonderful reliability values for that scale/ indicators (value of 0,856 without deleating items). But for my research model I am using the normal PLS algorithm (fits the research question better than does the PLSc) and there I get totally strange values (one is negative and two are under 0,3) - I just tried the PLSc because of these strange results for the construct and was very surprised about the results: with PLSc the reliability checks were all well. I do not understand what could be the reason for that and appreciate.
I didn't find the right solution from the Internet.