(Cleared out the quote cause it'd be way too long)
Sniping a translation, generally speaking, is when another person/group releases a current translation of content that's already being actively translated. As a rule of thumb, it's considered rude, but context dramatically shifts how a snipe is perceived.
First, there's the general principle that if a series of already actively being translated, it doesn't really need someone else also translating what's already being worked on. Unless the new translation offers something more than what's currently being provided by the current one (better translation, uncensored panels, higher-res scans, etc.), folks would generally say the effort of the sniper would be better served translating something else that isn't translated yet, has lost its TL, or has a noticably subpar translation.
If it's done with poorer quality than the current translation, with issues such as unedited machine translations, lack of typesetting, etc., it's taken particularly poorly. Cutting in front of the current scanlator just because you did it "faster", only for it to be slop, is insulting to the reader and the current scanlator.
There can also be the situation where the sniper is trying to advertise/solicit donations via their snipe, where they jump in to translate a chapter or two of a series just to direct readers to their own website/commission page/Patreon/etc., then do no further work on that manga unless paid. While the TL might be equivalent in quality, it's fundamentally scummy behavior.
Then there's also the part where someone coming in and sniping a series causes the original TL to drop the series, which if it's some aforementioned one-off sniper, means nobody's working on it anymore. I blame this mostly on the original TL, though I can understand becoming demoralized and wanting to quit after putting in constant effort on a translation only to see readers go and thank/praise the sniper for giving them some second-rate, machine-translated mess just because they did it "faster".
Those situations above are why, generally speaking, people take an initial poor view of sniping.
However, as mentioned earlier, if the new TL offers an improvement upon the existing one, it's much more positively received, especially when the current TL has some noticable issues that would make readers more than glad to have an alternative. Often this is barely even considered sniping because the effort the new TL is putting in generally far outweighs that of the current one.
Also, if a series has seemingly been abandoned (no scans for several official release periods), someone new stepping in isn't perceived as sniping.
All of which is to say, in this particular case, the reaction here is probably just going to be slight confusion more than anything. You didn't do a worse job than the current TL and you didn't do it for money, so there's no real reason to be upset about it. At the same time, with a current, equivalent translation already being done, there's no real "need" for this second TL to have happened, so there's not much benefit to it happening either.
So if you want to keep going on this series, power to you (though I'd strongly recommend reaching out to the current TL to see if you two can collaborate and have an easier (and possibly faster) time working on the series). If this was just a one-off for fun/experience, fair enough, though I would personally recommend doing that kind of thing on either the first chapter of a series (avoids any concerns with sniping) or on a chapter that has known flaws/issues with its TL (e.g. poor-quality machine translation scanlator sniped a chapter so the regular TL skipped it) or is outright missing.
Thanks for coming to my TED Talk on the social etiquette of conducting translation work on pirated Japanese cartoons. No refunds.