Paint it Purple

It does look like a K deficiency. But you’ve been adding bloom feeds. You could have lockout due to incorrect PH of the soil. With soil it’s important to monitor the ph and EC of the water going in and out. Next time you pour plain water through the pot measure the PH and TDS let me know! You can flush now as you’re close to the finish, that weird smell is normal had it on loads of plants it’s almost a putrid smell but it’s not rot. Best PH for veg in soil is 6.3 best PH for bloom in soil is 6.8 6.5 is a happy medium for both.