Do you use any type of mycorrhizae? Great white is what I use. Plants don’t give up their valuable sugar resources just for the fun of growing fungus gardens. They get a lot of things in return from the mycorrhizae, mostly in the form of nutrients.
Plants are able to get nutrients themselves through their roots, but they have a limited ability to do so. Their roots need to be in direct contact with the soil to absorb the nutrients, and plant roots only grow so small. Fungi, on the other hand, can get much smaller. Fungal hyphae can wedge in between individual bits of soil to cover almost every available cubic millimeter of soil. This increases surface area and allows the plants much greater access to nutrients than they could get by themselves. For many plants living under difficult conditions, they wouldn’t be able to survive at all without mycorrhizae. This little article may help understand what it should be implemented for, it builds a symbiotic relationship with the roots and forms a webbing that webs through your soul like a basket and helps to deliver the nutrients more efficiently throughout the whole plant. I bet if you use it and take care of the fungi you wouldn't have that problem anymore