VM web console using Firefox causes duplicate characters, Chrome and IE do not have issue

We are using VCSA 6.7 with five esxi 6.7 hosts & multiple vms are are running inside the esxi hosts. We are facing "Double Typing" issue when we open vm & start typing using Mozila firefox (Latest version) & The same issue do not shoe when we access v through chrome or IE. Looking for the earliest Response from your side

Thanks in advance