Thanks for the new bnsupport code, I have checked your logs and found some errors that could be the problem.
This is the first one:
105 [ 2019-11-12 17:33:52.1966 2975/7f3b34100700 age/Cor/App/Implementation.cpp:304 ]: Could not spawn process for application /opt/bitnami/apps/canvaslms/htdocs/: An error occurred while starting up the preloader.
106 Error ID: be162a96
107 Error details saved to: /tmp/passenger-error-queUWG.html
108 Message from application: encryption key is incorrect. if you have intentionally changed it, you may want to run `rake db:reset_encryption_key_hash` (SystemExit)
and this is the other one:
158 [ 2019-11-12 17:33:52.2013 2975/7f3b34f9f700 age/Cor/Con/CheckoutSession.cpp:285 ]: [Client 1-1] Cannot checkout session because a spawning error occurred. The identifier of the error is be162a96. Please see earlier logs for details about the error.
159 [ 2019-11-12 17:34:02.6787 2916/7f330e8c0780 age/Wat/WatchdogMain.cpp:454 ]: Some Phusion Passenger agent processes did not exit in time, forcefully shutting down all.
160 [Tue Nov 12 17:35:35.465257 2019] [mpm_prefork:notice] [pid 2969] AH00169: caught SIGTERM, shutting down
I would try if the suggested command by the log
rake db:reset_encryption_key_hash solves the first error.
The second one seems to be an error with swap. Can you check if you have it enable? If not, try to enable it.
Also, as it seems to be related to memory, can you check the memory of your instance to be sure it is enough?