Jaxx is a lightweight wallet that is not ideal for receiving frequent tiny transactions that mining efforts in general produce. Receiving frequent mining rewards (or even faucet rewards) will create a lot of micro transactions that will need to be queried when you want to spend your balances.
If you find that your Jaxx Wallet frequently freezes or will not initialize and you have been receiving mining/faucet rewards, it is possible that the sum total of your frequent micro-transactions have become heavier than our lightweight wallet can manage. We are recommending that you do not point your mining rewards to your Jaxx Wallet.
If your Jaxx Wallet app is experiencing issues resulted from receiving rewards and if you are concerned that it may be experiencing issues int he future, there are two options to consider:
1. Perhaps your pool or rig has the capacity to group your future rewards into larger, less frequent (daily or even weekly) payments. If it does, please consider that.
2. If you're experiencing issues managing the wallet/address you were sending the rewards to, simply create a brand new Jaxx wallet and import the Private Key of that address. This article here will take you through the steps for that.
3. If option 2 is not providing a successful resolution for you, the last resort would be to import your Jaxx 12-word Backup Phrase or the mining address Private Key into another wallet supporting the coin you were mining and manage the funds from there.