I have a problem when generating a pdf report inside python thread using the python threading library, the pdf is not generated with the corresponding css styles, in the odoo log I see the following warnings: 

- wkhtmltopdf: b'Exit with code 1 due to network error: ContentNotFoundError

- Failed to load http://127.0.0.1:8061/web/content/656-d6523a8/web.report_assets_pdf.css, with network status code 203 and http status code 404

- Failed to load http://127.0.0.1:8061/web/content/878-bce781e/web.report_assets_common.css

if it helps these are:

- the arguments for the wkhtmltopdf process:

['/usr/local/bin/wkhtmltopdf', '--disable-local-file-access', '--quiet', '--page-size', 'A4', '--margin-top', '5.0', '--dpi', '90', '--zoom', '1.0666666666666667', '--header-spacing', '43', '--margin-left', '0.0', '--margin-bottom', '5.0', '--margin-right', '0.0', '--orientation', 'Portrait', '--header-html', '/tmp/report.header.tmp.bm17ml23.html', '--footer-html', '/tmp/report.footer.tmp.gq5ppibu.html', '/tmp/report.body.tmp.0.qrtecjdv.html', '/tmp/report.tmp.tzl_dtf2.pdf']

- odoo version: 14 community

- python version: 3.8.6

- wkhtmltopdf version: 0.12.6

Thanks in advance for any assistance