What is your Shotcut version (see Help > About Shotcut)? Is it 32-bit?
Shotcut version 20.11.28
Can you repeat the problem? If so, what are the steps?
(Please be specific and use the names as seen in Shotcut, preferably English. Include a screenshot or screen recording if you can. Also, you can attach logs from either View > Application Log or right-click a job and choose View Log.)
Putting “Size and Position” above “Chroma Key” causes the filter to break.
Got it! I see now what happens; I wonder if it would be helpful to see what each clip looks like separately, and to see how you are using the SPR filter (e.g., show it with and without the SPR filter enabled). I am thinking the SPR filter is changing the position of what should be chroma keyed, and that is why it makes a difference whether it is before or after the chroma filter - but that’s just a guess at this point!