DNS Cache Size cause crash?

I have a CCR1036 that I tried to replace a RB110AH with and it kept locking up. I have reset the config and am setting the config up from scratch for the second time now comparing setting to the rb1100ah.

Last time I did not notice that the dns cache size starts out at 2048 and the udp packet size at 512 by default in the router.

The current router in place has a udp packet size set to 512 and a cache size of 20480

I notice that I use about 2400 cache on average in the old router.

Would not having the cache size set high enough cause the unit to crash?