WetGeek Maybe the next sync will produce a pleasant surprise, and I won't need the work-around any more.
One last note on this: once again, I've proven that after the laptop has hibernated one time without a browser running, it behaves perfectly thereafter. So I'm going to continue as I proposed in a previous message. I'll just work all week as I'm accustomed to doing, and hibernate this laptop every night.
Whatever the root cause of this problem is, this process appears to fix it until after the next complete shutdown.