Hi Robert, thanks for the question.

The sweetness of your berries can be affected by several factors.  Both strawberry and raspberry sweetness can be related to soil issues like pH and nutrient balance. A soil test (Home | MSU Soil Test) can help determine any adjustments that may be necessary.   Over fertilizing with nitrogen, is said to reduce sweetness. Consistent moisture is important, but overwatering can cause fruits to be less flavorful and sweet.  Full sunlight is needed for good sugar development in the fruits.   Don't get impatient, pick fruit when fully ripened, they do not continue to ripen once picked.  Low soil temperature may affect sweetness, so it is important to apply mulch properly.  Consider the variety, some are just sweeter than others. Check out the following links:

Growing Strawberries in Your Home Garden | OSU Extension Service (oregonstate.edu)

Growing strawberries in the home garden | UMN Extension

How to Boost the Sweetness of Your Strawberries (Guide) (strawberryplants.org)

I hope this helps,