First, note that in our 2 year history this is the first mandatory where the network required our users to upgrade before the mandatory cutover height. We had an increase in our governance protocol version to 70750 from 70737, and when 60% of our sancs moved to 70750, the older biblepay clients stopped recognizing those sanctuaries as official, meaning they then need to upgrade early (or go on a fork) - this explains why 75% of our network upgraded 3 days early (we were shooting for Dec 26th and all this happened around Dec 23rd).
So apparently what happened is you mined on the prior version, 1 mil bbp on the low diff chain. When you upgraded, all the blocks mined on the side chain got erased. Notice how your outbound transaction to your mobile is orphaned also. Thats because it was sent on a sidechain, and the txid is not on the main chain.
The reason your last mined transaction is in immature is because its not 120 deep yet but its probably officially mined.
Just run the client with -zapwallettxes=1 and restart and it will fleece the orphans out of the wallet - note it will remove all the mined and the outbound tx and leave all official txes.
Good luck going forward.
Is it possible in future display a message about necessary upgrades (or just about next available versions) right inside the wallet? May be as a Prayer Request, I don't know...
Also, I would like BiblePay to support a distributed computing project Rosetta@home
p.s. https://wiki.biblepay.org/PODC_Setup#PART_I:_Calculate_Rewards - so actually we can't calculate a reward for PoDC mining, right? I like charity and BOINC, please don't get me wrong, but for now I need to return my investments in hardware... Later (pls check my signature if you didn't do this yet) it will not have such a meaning for me like it has now...