Low lubricant level in the cv joint is a common cause. The cv joint has to heat up before it is obvious. Add some very heavy oil to each side to see if that is enough before too much damage is done.

Just loosen the inner clamps and feed a tube in through the boot to axle space feeding it with something like a turkey baster. Almost 80 percent certain this is your issue.

The longer you drive it like this the higher the odds become of the cv joint being destroyed. The clue is always almost the same. Car has to be driven until the joint components heat up. From the lack of lubrication.

Let us know if this solves it. You still stand a good chance as they are not clunking all the time yet. Once they are clunking all the time it is usually too late.

The original lubricant was heavy oil. Some use grease but if you have taken apart damaged cv joints you will have noticed the grease has lost the contained lubricant and only the soap filler without the oil is left. Usually well displaced from the area where the lubrication is needed. Straight heavy oil does not do this.