Q.Meyer Lemon in backyard, 6′ tall
I’ve been seeing flowers for months, but do not see any green fruit in addition to the lemons I’ve been picking. Had the tree about 20 years and never had this problem before-no new fruit!
Best, Ben Preyer, San Diego

Getting the flowers to set fruit takes the right amount of sunlight, water and nutrients.
And pollination! Though Meyer Lemon are self fruiting, another citrus nearby will help.
Here are some articles that will help you pinpoint the issue.
https://www.gardeningknowhow.com/edible/fruits/lemons/growing-meyer-lemons.htm
https://www.gardeningknowhow.com/edible/fruits/lemons/learn-about-fertilizer-for-a-lemon-tree.htm