Hi stardental ,
Glad to hear that you were able to find out what's causing the issue!
You could perhaps exclude Buttonizer from Autoptimize so that you can use both plugins at the same time.
Add this to "Exclude scripts from Autoptimize" under Javascript Options and"Exclude CSS from Autoptimize" under CSS Options in Autoptimize:
If your using Buttonizer free;
, wp-content/plugins/buttonizer-multifunctional-button/assets
If your using Buttonizer premium;
, wp-content/plugins/buttonizer-multifunctional-button-premium/assets
Please let me know if this works for you! 😃