Hello and welcome to Apple Support Communities nirbhay1622,
We understand that you’re unable to copy and paste from one device to another. We’d be happy to provide you with some information that can help.
You’ve already done some good troubleshooting by making sure that Handoff is enabled on your devices. Next, we’d like to have you turn off this setting on both devices, restart them and then enable Handoff again. If you need assistance with this, the article below can help.
Use Universal Clipboard to copy and paste between your Apple devices
Let us know if the issue remains.
Thank you for using Apple Support Communities.