Currently I am unable to install most addons and have tried for days without any success. I say "most addons" because, for example, https://apps.odoo.com/apps/modules/12.0/app_odoo_customize/ works for me (appears as installable on the app list and can install) but none of the following (that simply don't appear for install):

https://www.odoo.com/apps/modules/12.0/hr_dashboard/
https://www.odoo.com/apps/modules/12.0/document_management_system/
https://www.odoo.com/apps/modules/12.0/dhx_gantt/
https://www.odoo.com/apps/modules/12.0/project_report_pdf/

Haven't tried more but I'll try out any other one you'll send me so as to check what's the problem.

Some possibly useful data:

-> Using Bitnami Odoo stack.
-> Version at the Settings dashboard: Odoo 12.0-20191215 (Community Edition) 
->Followed the whole guide for addons in Odoo: unzipped everything in separate folders inside [odoo path]/data/addons/12.0/, restarted server, updated apps list in debug mode, they still don't appear. 
->cat /proc/version 
Linux version 4.9.0-11-amd64 (debian-kernel@lists.debian.org) (gcc version 6.3.0 20170516 (Debian 6.3.0-18+deb9u1) ) #1 SMP Debian 4.9.189-3+deb9u2 (2019-11-11)
->Tried giving chmod 777 to everything under modules and changing owner to daemon:daemon without luck. The Sunpop module still appears but not the rest. 
->Uninstalled & reinstalled the full virtual machine in case there was a problem on my side. Didn't try with another preinstallation 

I'm just started, but couldn't find any related documentation after days of searching.

Thank you for your time!