Ya, I had a similar problem with my Clam Mac Client.  For me, it saw the Clams on restart, however as I was on support chat with Clam tech, he said "Rescan".  But alas, I found a hefty amount of Clam and I need not rescan.  It's worth it. 

I actually mined 5 coins since that time.  Having missed out on the mining phase of crypto so last year, finding an extra coin in my client in the morning is quite rewarding! 

Good luck fellow Shibe and Cheers! 

/s/