Malwarebytes problem?

Over the past week, my computer has locked up three times--to the point
where I had to turn it off manually. I suspect the problem is
Malwarebytes. I run the free version when I want to check for malware.
However, the last time I did an update, it installed a trial version of
the full program. (I don't remember being asked to confirm that I wanted
it.) What made me think of this program being the problem is that today
I got a message from the program that I had three more days of the trial
version.

Assuming that it is Malwarebytes causing the problem, what is the best
approach for dealing with it? Should I uninstall Malwarebytes and then
try to reinstall the free version? Wait for the trial version to end?
Something else?

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Thank you,
Jo-Anne