How to resolve frequent freezing on M4 iMac with Grammarly Desktop and Zoom?

I wanted to reply to my earlier post (June 4, 2025) about this, but Apple locked that discussion:

New iMac M4 Freezing up after 15.5 update - Apple Community

My client continued to delete TimeMachine localsnapshots to temporarily fix the freezing, but after a couple of months that stopped helping.

So my client had Apple support completely erase the M4 iMac and NOT restore anything from TimeMachine.

He kept it clean except for installing a few main apps: Chrome, Zoom and Grammarly Desktop (different from Grammarly's browser extension).

The freezing continued and I finally experience it numerous times during our remote tech session.

Activity Monitor and EtreCheck Pro never hinted at the culprit -- very frustrating!

It seemed like a hardware problem.

If Apple wouldn't replace the M4 iMac for free, my client was going to buy a new one and trade in the old one, answering Apple's question about its condition as "like new" based on Apple's own claim that nothing was wrong with the hardware.

But as a last thing to try, I prevented Grammerly Desktop for macOS from loading at startup and restarted the M4 iMac. The problem stopped! I couldn't believe it. At no point in my client's, my and several Apple techs' long troubleshooting sessions, did Activity monitor or EtreCheckPro or sytem logs I found point to Grammarly Desktop. And my client rarely uses it. But it loads at startup and has a menu-bar icon with a pull-down menu.

It's been a couple of months since we removed Grammarly Desktop for macOS and my client reports all clear -- not a single instance of the freezing while using Zoom or any other app.

The intermittent freezing was most apparent when using Zoom, which my client needs for work.

It seems Grammarly Desktop of macOS is the devil, especially in combo with Zoom.

I have numerous clients with various M4 Macs and Zoom who never had this problem.

This client is the only one with Grammerly Desktop for macOS. A few other clients have Grammerly's browser extension in Chrome, Brave and Firefox and haven't reported any freezing.

I'm too tired to hate Grammerly Desktop for macOS and instead rest assured knowing there's a meteor in our solar system with Mac Grammarly Desktop's name on it.

Un-@#$%@#$%-believable!!!

[Re-Titled by Moderator]

Original Title: SOLVED: M4 iMac freezing often for 10 - 20 seconds. Sequoia and Tahoe. SPOILER: it was Grammerly Desktop.