Shade plant trouble
This looks like the hosta was subject to sunburn. This is not a good location for the hosta. Hostas generally prefer high-filtered shade with perhaps one-quarter to one-half of the day in morning sun. Hot afternoon sun will scorch most hostas and should be avoided. We also notice that the hosta is located next to a pavement which can reflect heat.
All you can do is tolerate this or transplant the hosta to a shadier location and select another species of plant for the location. It is important to match the plants to the site.