the same for me.
mydbr build 4653
export to pdf and xlsx ends with error. can not write (or access) to /tmp directory.
whith select 'dbr.export.options', 'debug', 1; in report i get:
~~
To test wkhtmltopdf pdf generation, copy the following command into the server's command line.
myDBR saved the generated HTML file into /tmp/mydbr_export_2147188892.html. File size is: 36351 bytes.
usr/local/bin/wkhtmltopdf --margin-top "20" --header-spacing "8" --header-html "https://report.kmv.local/user/export_header_pdf.php" --replace rdate "2022.06.29" --replace rtime "16.35.14" /tmp/mydbr_export_2147188892.html debug_output.pdf
~~~
when i run this command with root user then pdf is exported ok.
sorry for my english ;)