squeeling noise from underneath car

Has anyone checked out the CVT?

I believe so. When the second mechanic I took it to put it up on a lift, he determined that there was a transmission bearing going bad.

Usually any driver or passenger can differentiate FRONT from REAR bearing noise locations. So is it front or rear? If rear, use a stethoscope if necessary to differentiate left from right; the louder side is of course the defective one. If the noise is from the front then a mechanic will have to discern if it's either front wheel bearing ($200) OR an internal CVT bearing, for which there is no repair except swapping the CVT for a good used one (about $2k). There is a VERY small chance that it's an inner axle joint (DOJ)...another $200 quickie.

It sounds as if it's in the front but based on the fact I've had two pretty reliable mechanics look at it and determine its in the transmission, I'd probably have to concede to that myself. Only reason I thought it might have been a bearing was because you can hear it going around turns but it's also very noticeable going straight at speeds as high as 50mph.

I would go with the opinion of people that have looked/listened first hand. We can't hear anything out in internet land.

See above again; differentiate front wheel bearing from internal CVT bearing noise with stethoscope as necessary. If two guys are sure it's the CVT well there you are. If necessary just drive it until it's so loud that differential diagnosis becomes easier.