[PS4] Frequent Lag with Slow-Mo; Stutter/Freeze While Running After Patch 10

I'm playing DA:I on a PS4 that is very rarely used and only about six months old. I don't believe it's a hardware issue, especially since I've played the game without any of these issues before - including for a total of about nine hours while Patch 10 was downloading and immediately before installing it. (I have very slow internet, to say the least.) Everything worked fine, there was never any noticeable lag, and certainly no moments of slow motion.

Then, after Patch 10, things have gone a bit pear-shaped. Err, not literally, thankfully.

The first issue I noticed is that there are frequent bouts of the sound taking a while to catch up with the game. It used to happen only if the game had gone a long while without using sound effects, but now it's almost constant. From the kissing noises happening long after Cullen has pulled back to ability sound effects happening long after the spells etc. have already appeared visually, things just keep falling out of sync and it's no longer infrequent enough to count as a random glitch. It's nearly all the time! This also sometimes happens with the visuals and the spells themselves. For example: I would cast Energy Barrage, then nothing would happen so I'd cast it again. Then I'd give up and do an auto-attack. After a second or two, Energy Barrage would cast followed by a normal attack. In many other cases, I'd have to cast blindly because things were lagging a couple of seconds behind my input.

During this, the battles would keep going into what I can only describe as a brief slow-motion moment. I first noticed this while battling the Sandy Howler dragon, though it also began occurring on other enemies. Though I googled it and it said that this was the result of cross-class combos etc., this randomly started happening and I hadn't levelled up or changed gear etc. on any of my characters between the last battle and the one where I noticed this. Nor had I ever noticed it before. From that point forward, it became extremely frequent - far more than I would presume natural for cross-class combos etc. to occur. Every battle, no matter the enemy, became plagued with these little slow-motion moments, to the point it made actually doing battle quite a bit difficult.

When I reached the end-game with my character, just before the battle began I had to pause and attend to real life responsibilities. It wasn't any longer than about 45 minutes that it spent paused. When I resumed, I was able to cast one spell before the game crashed to an application error. Sadly, I didn't think to take down the error but I did send it through as a report to Sony using the automatic system that popped up for doing so. I was able to reload the game and resume play from the auto-save which happened directly before the battle, but again the battles were plagued with these slow-motion moments.

While at the time I'd thought that they were just combos, the out of sync audio and delayed skill/ability usage also kept happening. I powered through regardless, and made it all the way to the end of the game. After that, I used up all my extra gold to buy some schematics I wanted and synced to the Golden Nug in Skyhold. Then I loaded another, pre-created character of mine who has only a couple of hours of gameplay and is stll at Haven.

While having her run around Haven looking for the Golden Nug to sync, I noticed that she'd randomly pause in slow-motion fashion mid-run. At first I thought she'd maybe gotten caught on a rock or something, but it kept happening even in the middle of nowhere on the ice. Partly, it seemed random, but there were some locations where I could consistently trigger this (such as near the giant doors that lead between where Cullen stands and the rest of Haven) while running. While walking, it still occurs but as a slightly less noticeable stutter in the animation. So I'm definitely convinced now that something has gone wrong and for some reason DA:I isn't behaving properly with my PS4 anymore (or perhaps vice versa, though it was perfectly fine pre-patch).

I've never had anything like this happen before with this or any other game, so I'm really perplexed and hope that it can be fixed. Preferably, I'd like to avoid anything that involves losing saves or having to delete and reinstall the game because my internet is so slow that just Patch 10 alone took 26 hours to download.

Edited to Add: I feel like I should also mention that ever since the patch, my load times have moderately increased. This is even after deleting all unnecessary saves I had to lighten the clutter and make sure I had space for new characters.