The leaves on my standard bay in a pot are turning yellow.
Is the pot free draining? Is it pot bound? Do you feed if? Are the leaves still normal shaped or are they distorted?
I increased size of pot this year and added nutrients to new soil. The pot is free draining.
Have oyu got a picture of the yellow leaves?
Mine has a few leaves turn yellow and fall each year - I regard that as normal, but it reminds me to keep the watering up (although they like it free draining, they still like plenty of watering) and I also spray the leaves with dilute seaweed feed which always seems to perk it up.