Instruments sound wrong--Especially piano and violin

I have been using Musescore 4 very well since it came out. I have really enjoyed the strings-- and the mixer. I was successfully adapting my Musescore 3 scores to 4.
However.
Now every instrument sounds wrong. All the strings sound like the cello .
I really need this to work for my online students. They receive my scores and they are unusable.
I am shown violin 1 or 2-- except when I choose to set up as a string emseble.
I have uninstalled and reinstalled Musescore and the Hub.
Here is how my test example sounds on Musescore.com

https://musescore.com/user/175327/scores/11753722/s/A7R5LI?share=copy_l…
I would be grateful for any guidance!
LisaJo