I don't know why that would be true, Rusty. Solder that I'm aware of does not magically increase it's melting temperature
I agree with Crackedback, EXCEPT that so much of the time, crimped terminals are not properly crimped. Cheap import crimpers, or working in dark, tight access is likely a big cause. AND SOME BRANDS OF TERMINALS JUST SUCK!!!
Many dont have a long enough barrel for reliable crimp, and some of the yellow (no10) terminals are WAY too light material to be hardy and reliable
