Why the change in visa type from Visa to Entry Clearance and the reduced validity from 2 years to 6 months

In 2018 I applied for UK standard visitors Visa and was successfully issued 2-year with Visa which has the resemblance of the schengen Visa. In 2021 I applied for another 2-year visa and instead I got Entry Clearance Visa and for only 6 months. Why the change in visa type and the reduced validity time. Can I get refunded for the difference in visa fees of 2 years (GBP390) to 6 months visa (GBP 95).