I am using IG for automated trading only, but I still use it as a reference.
I am trading manually with another broker and I happened sometimes to have my SL triggered by few pips as well as my TP triggered by a few pips, as well as my SL not triggered by 1.2 pips then becoming a winning trade!
Las week a had a losing trade by less than 4 pips, then the price went the other way round and it would be a winning trade right now, in this case after placing my limit order I was thinking about the correct placement of my SL, because there was another further place thant could have fit better I thought, but I decided not to change my order to risk less. And I lost!!!!
I also have crosschecked 3 different brokers, several times, and in normal situations (far from important news where volatility may bring even 10-20 pips difference in prices among brokers) prices were less than 1 pip apart!
I cannot say much about your case, because only you know the real facts, but I don’t believe in a BIG BROTHER.
I don’t think Deutsche Bank or JP Morgan etc…. will care much about a couple of our pips! They even do not know about our SL and TP, only our broker does! And adding some pips to catch your SL may trigger someone else’s TP!
There are some “odd” (to say the least) Market Makers and everyone should stay away from them. Their reputation is jeopardized and they have to change name quite often. They are best placed in “exotic” or less controlled countries!
Some brokers may “take advantage” of high volatility just to increase slippage on the spur of the moment, but even slippage may turn to your favor sometimes!
I trust brokers with decades of activity and experience. For sure they are common companies and as such they need to make profits, but traders are their “daily bread”, wasting that bread may starve them in the long run!