Hi Owen EvansCU,
Thank you for posting in this community.
To investigate this issue, I created a dropdown list with 100 options using Forms. As you can see the below screenshot:
But, it doesn’t slow down the Forms program and my web browser. So, I am afraid this issue may be related to your web browser or your device.
And to narrow it down, you may try the following suggestions:
- Turn off some of the background programs that you don’t want to use on your device to speed up Forms.
- Please try to clear the browser cache and make sure that they also select the Cookies and website data option.
- Please try to use another web browser like Edge.
Best Regards,
May