Try re-running `make provision` one more time. If this doesn't help, comment out the last task in `/ansible/clamav/tasks/install-clamav.yml` & try restarting ClamAV manually.
ClamAV restart can time-out due to slow disk read/write speeds (if using HDD) and lack of memory. To resolve this, provide the machine with more RAM. Current implementation has it set to `1024` MB (which should suffice for the majoirty of host machine configurations). If you're using SSD, you can lower it to `512` MB.