Description of the problem
I think I may have run across a bug with fig.meca when attempting to plot from a file. Column names are being plotted in the bottom left corner, and the issue disappears when column names are removed from the file.

Full code that generated the error

import pygmt
import os

# Main File Path ----------------------------------
main_dir = r'C:\Users\USER\Desktop\TESTING'

# Save Path ----------------------------------
save_name = os.path.join(main_dir, 'Results', 'map_TEST.png')

# Focal Mechanism Path ----------------------------------    
focal_mecha = os.path.join(main_dir, 'Data', 'selected_fm.csv')


fig = pygmt.Figure()

fig.basemap(
    region = [-115.85, -115.35, 32.80, 33.38],
    projection = 'M6i',
    frame = True
)
fig.coast(
    land = 'grey',
    water = 'lightskyblue2',
)
fig.meca(
    spec = focal_mecha,
    convention = 'aki',
    scale = '1.0c',
    offset = True,
    )

fig.savefig(save_name)
print('done')

System information
PyGMT information:
version: v0.4.0
System information:
python: 3.9.5 (tags/v3.9.5:0a7dcbd, May 3 2021, 17:27:52) [MSC v.1928 64 bit (AMD64)]
executable: C:\Users\USER\AppData\Local\Programs\Python\Python39\python.exe
machine: Windows-10-10.0.19043-SP0
Dependency information:
numpy: 1.21.0
pandas: 1.2.5
xarray: 0.18.2
netCDF4: 1.5.7
packaging: 20.9
ghostscript: 9.54.0
gmt: 6.2.0
GMT library information:
binary dir: C:/Users/USER/AppData/Local/Programs/Python/Python39
cores: 4
grid layout: rows
library path: c:/programs/gmt6/bin/gmt_w64.dll
padding: 2
plugin dir: c:/programs/gmt6/bin/gmt_plugins
share dir: c:/programs/gmt6/share
version: 6.2.0

My data:
selected_fm.csv

My map output: