variable products images not showing

All product images sizes are set to 300×300 in woocommerce. When I try add an image that size to a product variation, the image does not appear when I select the variation on the front end UNLESS I load in an image that is 150×150 or smaller.
Initially even that size did not work when the thumnaisl were set to be 90×90.
I do have a price entered.
I’ve cleared caches and test on mac Chrome and Firefox. I’m getting a javascript error that tells me I have mixed content, but if you roll over the place where the image is supposed to be long enough; the https appears. Either way, it does not explain why the smaller images appear.

Woocommerce version 2.5.

Can anyone help? I’ve spent hours trying to figure this out.

https://wordpress.org/plugins/woocommerce/