It sounds like you may be referring to either Universal Clipboard or Handoff, depending on exactly what you were doing with the Chrome tab.
If you were copying the URL or other content from a Chrome tab on your iPhone and then pasting it on your Mac, that is Universal Clipboard.
Apple says it requires both devices to be signed in to the same Apple Account, with Wi-Fi, Bluetooth and Handoff enabled, and the devices reasonably close to each other. Apple: Use Universal Clipboard
On your Mac, check System Settings >> General >> AirDrop & Continuity and make sure Allow Handoff between this Mac and your iCloud devices is turned on.
On the iPhone, go to Settings >> General >> AirPlay & Continuity and make sure Handoff is enabled. Apple: Use Handoff
If, however, you mean that you could previously open or continue the actual Chrome tab from your iPhone on your Mac, that is different from Universal Clipboard.
In that case, it would be helpful to know how you were doing it, for example, whether you were selecting the iPhone’s tab from Chrome on the Mac under Tabs from Other Devices, or using a Handoff prompt.
For the Universal Clipboard issue, Apple recommends checking for available software updates and restarting both devices.
After that, try copying a short piece of text from the iPhone’s Notes app and pasting it into TextEdit on the Mac.
If that works, try copying the URL from Chrome.
That should help determine whether the problem is with Universal Clipboard generally or specifically with what you are copying from Chrome. Apple: Use Universal Clipboard