R quantmod: Connection error when pulling data

I am trying to pull some stock quotes for Amazon via quantmod. I just downloaded the package for the first time and am using R x64 3.5.3. When I run this code:

library(quantmod)
amzn = getSymbols("AMZN",auto.assign=FALSE)

I get the following error:

Error in curl::curl_download(cu, tmp, handle = h) : 
  schannel: next InitializeSecurityContext failed: SEC_E_INVALID_TOKEN (0x80090308) - The token supplied to the function is invalid

Any idea what could be causing this?