sump filter/screen is a possibility
also...
when you say the fluid is 'very pink' that makes me think it may have water/moisture contamination. The fluid is supposed to be red.

you may want to check the radiator and overflow resivoir and see if there is any pinkish contamination in those areas. The reason i ask is the transmission cooler goes through the radiator and if the trans cooler core is leaking into the cooling system this would explain the fluid contamination causing the pink fluid.
And if the fluid inside the transmission gets airiated (full of air bubbles) it could cause it to not pick up fluid and make it do as you described.