@danx55 for screenshot better use google voice assistant.
"The quieter you become-the more you are able to hear..."
Hi @danx55 Do you have Wake up Activated? otherwise should be work ok by pressing side Button and saying Take Screenshot,possibly may wish to record voice again. If still issues idea to clear the Data and cache. Go to Apps-Bixby Voice-Storage-Clear Data and Cache. Some more information here https://www.samsung.com/us/support/troubleshooting/Bixby Voice
Do not have issues myself, obviously Google Voice is an alternative.
I do not work for Samsung or make Samsung Products but provide independent advice and valuable contributions.
My Device- S21 Ultra 5G ( SM-998B/DS ) CSC= BTU , 12GB/256GB
One Ui 5.0,Android 13 .