Sorry, I do not wish to send the save file, for different reasons.
Also, in case there is any confusion, I am describing two bugs, and they appear unrelated, at least the bugs can be reproduced on my system without the other bug's items being involved. I have now spent some more time investigating the bugs:
Bug 1: Is with the ring crafted by a Golden Goblin, where the stat boosts it gives are apparently bugged. I tested it a bit more, and it appears that it might be the combination of "+2 to Strength" and "All Stats Increased by 3" that bugs out. The ring, at least on the Stats Page UI, gives +5 Strength, and no other Stat increases, even though according to its description it should give +5 Strength and +3 all other Stats. I have isolated the bug to just the ring by having no other items equipped on the character than that Golden Goblin-crafted ring.
Bug 2: Is with the unique shield "Guiding Eyes" that the wounded paladin left behind as well as a wand crafted by another Golden Goblin, and quickswapping. The wand has a number of different properties, including +4 Constitution and "Increases Mana by 5". My character has 12 base Constitution, so if the wand is not held, the shield cannot be held, since the shield Guiding Eyes in this run requires 14 Constitution. I have isolated the bug to just those two items by removing all other gear. I also had a torso-body-armor depend on the extra Constitution from the wand, but I tried with just that torso-body-armor and the wand, and I could not replicate the bug. I have also isolated the bug to quickswapping, by either clicking in the inventory on the "II" button or by using the quickswap hotkey, and having the shield Guiding Eyes fall off due to the wand no longer being present and not giving its Constitution bonus. I can not replicate the bug by manually clicking on the wand to remove it and holding it in my cursor and that way making the shield drop due to not having sufficient Constitution, it is only by quickswapping that it occurs. The bug gives increases not just to Mana and Intelligence, but also Armor and Defense, the properties that the Guiding Eyes shield gives in this run (apart from the "15% for Damage Absorbed by Mana" property, but I can not see the effects of that from the Stats Page UI). Each time that the quickswapping is done, the properties are increased, and after having been done many times, giving very high values of Intelligence, Mana, Armor and Defense. What is important to note is that when I load the save again (for instance by quitting to the menu and loading the Iron man save again), the character does not keep the extra Intelligence stat, mana, armor and defense, but the bug can still be replicated by doing the quickswapping again. I do not have any other shield that requires Constitution to be held, so I do not know whether the bug can be isolated to the unique shield Guiding Eyes or if it is a general bug involving left-hand (or shield in case idol items do not bug out?) equipment.
Is there anything locally you might want me to do, that does not include sending the save file?