ggsave and `device=cairo_pdf` gives inconsistent spacing between text letters

Here is a reproducible example (at least on my machine it reproduces the error I have with a more complicated plot).

Making a cumulative trend line in ggplot?

I have this dataset in R:

Making a cumulative trend line in ggplot?

I have this dataset in R:

Making a cumulative trend line in ggplot?

I have this dataset in R:

Making a cumulative trend line in ggplot?

I have this dataset in R:

Making a cumulative trend line in ggplot?

I have this dataset in R:

Making a cumulative trend line in ggplot?

I have this dataset in R:

Converting a count histogram into a percentage histogram?

I have this simulated dataset in R that contains information on the same patient visiting a hospital over a different set of dates:

Converting a count histogram into a percentage histogram?

I have this simulated dataset in R that contains information on the same patient visiting a hospital over a different set of dates:

Converting a count histogram into a percentage histogram?

I have this simulated dataset in R that contains information on the same patient visiting a hospital over a different set of dates: