Congressional Republicans asked Social Security's Office of Inspector General (OIG) to see whether political appointees at Social Security were manipulating the agency's responses to Freedom of Information Act (FOIA) requests. OIG found no evidence of this.
I have no idea why the GOP would think there was a problem with political interference with FOIA requests at Social Security. However, there is a big FOIA problem at Social Security. FOIA requests at Social Security take forever! Months and even years can pass without a response. This isn't because of political interference. It's because of lack of resources. It's the same at other government agencies. FOIA is a mess but the problem isn't political.