It's probably safe to say that normally the summer is not the best time to buy a camping fridge, pricewise. Although now with the virus thing there may be comparatively good deals. And, yes, the China tariffs, whether actually applied or not, may also play a role.
Seems some of them have done this, as in tagged on a “peak season”, or a “COVID” tax, but not everyone. Like OP, some of the Dometics I looked at have went up since last year, by up to 200 bucks.
If anyone is interested in joining us for the IceCo group buy I linked above, the coupon is active now and everything is 25-38% off.