Hello Alisson ..
The mongodb2 node hasnt been updated for more that 4 years.
and other people have reported some problems with it also.
Can you try unistalling it and installing the more recent node-red-node-mongodb
ps. you can only have one version installed .. so make sure to uninstall the older one first
With newMsg.payload = { 'timestamp' : '/28\/08\/2021/' };
are you trying to use a regular expression pattern ?
try without the quotes
newMsg.payload = { 'timestamp' : /28\/08\/2021/ };
or
newMsg.payload = { 'timestamp': { $regex: '28\/08\/2021' } }
