Yes, my experience with SOAP is that even well written and maintained clients only work out-of-the-box with like half of the vendor-supplied services you come across.

In many cases, I'll simply formulate xml requests myself and use a generic http request client because the implementation ended up being simpler & easier to maintain than all the confusing hacks I had to do to make zeep or suds (the most popular SOAP clients implemented in python) function properly.