Peer certificate authentication failure

Dear Rstudio community,

Until recently, I was able to use the "sdmpredictors" package to download geotiff files from Bio-oracle, but now I get the error that the "Peer certificate cannot be authenticated with given CA certificates". I can, however, access the weblink and file via my web-browser, suggesting that there is no issue with the CA certs. I have checked my keychain and the ISRG X1 root certificates appear up-to-date and working.

I've tried uninstalling R/RStudio, but to no avail. I'm running OSX10.14.6 Mojave and R 4.1.1 on a MacPro. Any thoughts/help would be much appreciated.

The code and error returned is shown below. I then attempted to download using utils::download.file() using curl, but this also fails.

bathy <- sdmpredictors::load_layers("BO_calcite", equalarea = FALSE)

Error in utils::download.file(layer_url, path, method = "auto", quiet = FALSE, : **
** cannot open URL 'https://bio-oracle.org/data/1.0/BO_calcite.zip'

** URL 'https://www.lifewatch.be/sdmpredictors/sysdata.rda': status was 'Peer certificate cannot be authenticated with given CA certificates'**

Using utils::download.file() returns the following:
curl: (60) SSL certificate problem: certificate has expired

Crosspost Reference:
Data download error · Issue #14 · lifewatch/sdmpredictors (github.com)