NO JOY AvantFax Quality Outbound Fax

[cantVOIP]

Running IncrediblePBX2021 on Ubuntu. Asterisk 18.13.0 and Incredible GUI 15.0.22.34
I've set up fax successfully. The quality of incoming faxes is great, but the quality for outgoing faxes using AvantFax and PDF is poor to a point where small letter is unreadable. Can anyone advice on how to improve outgoing fax PDF quality?

Thank you!

 

[cantVOIP]

To add more context. This is what I see under /var/spool/hylafax/log/c000000003
Dec 08 22:19:43.98: [27747]: REMOTE best rate 33600 bit/s


Dec 08 22:19:43.98: [27747]: REMOTE max A3 page width (303 mm)
Dec 08 22:19:43.98: [27747]: REMOTE max unlimited page length
Dec 08 22:19:43.98: [27747]: REMOTE best vres R16 x 15.4 line/mm
Dec 08 22:19:43.98: [27747]: REMOTE format support: MH, MR, MMR, JBIG
Dec 08 22:19:43.98: [27747]: REMOTE supports T.30 Annex A, 256-byte ECM
Dec 08 22:19:43.98: [27747]: REMOTE best 0 ms/scanline
Dec 08 22:19:43.98: [27747]: USE 14400 bit/s
Dec 08 22:19:43.98: [27747]: USE error correction mode
Dec 08 22:19:43.98: [27747]: SEND file "docq/doc5.pdf;f1"
Dec 08 22:19:43.98: [27747]: USE A4 page width (215 mm)
Dec 08 22:19:43.98: [27747]: USE unlimited page length
Dec 08 22:19:43.98: [27747]: USE 7.7 line/mm
Dec 08 22:19:43.98: [27747]: USE JBIG
Dec 08 22:19:43.98: [27747]: USE 0 ms/scanline
Dec 08 22:19:43.98: [27747]: SEND training at v.17 14400 bit/s