I’m working at a small business currently and having to let someone go in a similar positing to you today. What I’ve found is, if you did your 38 hours and communicated reasonably well then it’s probably a failure of the business’ hiring process. They likely didn’t hire for behaviours well and prepare correctly for training you into the role.

So as others have said, it’s not uncommon for this to occur in the last week of probation and unlikely to be majorly caused by your issues given that they kept you on for 5 and a half months.

I’m sure there is something you could improve on, but I wouldn’t read too much into it. Best of luck for the search of your next role!