sending byte values greater than 127 adds extra bytes - Tera Term Ticket #40584 on OSDN

I am running into a strange behavior where any time I use send to send bytes greater than 127 (i.e. bytes without standard ASCII characters) then a series of seemingly arbitrary bytes are sent instead of the offending byte. I am communicating over asynchronous serial at 19200 baud and using Tera Term v4.105.

For instance, if I run the macro sendln 27 127 100, I receive on the other end the following bytes (as expected): 27 127 100 13 10, however, if I run the macro sendln 27 128 100, I receive 27 226 130 172 100 13 10. The 128 is replaced with a 226 130 172.