I noticed that I cannot see some posts or comments from this account on this instance. Some of which are my own posts/comments. These are not posts/comments that have been removed nor does it have to do with bans or blocks.
My own posts/comments for which I receive replies, I will see them in the "messages" section and will be able to access them from there. The posts in communities will be displayed, but comments will show as unable to view
If I log in using an account form another instance, like sh.itjust.works for example. I can see all the missing posts and comments normally.
Here's an example of a post that I made in the Montreal community. I doesn't appear when using my lemmy.ca account, but will appear when using my sh.itjust.works account.
Do you have English, French and Undetermined selected in your language settings (on desktop, control+left click each)? It's a frequent issue users encounter just from unclear wording that makes content seem to "disappear".
If it's not that, then some screenshots could help find the source of the issue.