@PeDre - thanks for checking. I see it works for you at 8244. What is that program you used ?
When I run my pyvisa program with different values for chunk_size:
DS1054Z = GPIB.open_resource([_ for _ in GPIB_Resources if re.search('^USB.*:DS.*INSTR$', _)][0],chunk_size=3000)
it doesn't appear to fail as often, but there are definite slow downs at some points (watch the results scroll by) -- they appear to be at 64-count intervals. In my case, starting at 8200:
for NPOINTS in range(8200,30100):# fails at 8244 first
gives a slowdown (but not a fail) at 8226.
3.6.5 |Anaconda, Inc.| (default, Mar 29 2018, 13:32:41) [MSC v.1900 64 bit (AMD64)]
visa 1.9.1