This is something I don't think is worthy of a question, but it is something I noticed happening to me, and I was curious if there are any other cases. For me for somereason I have begun switching my vowel+"r" letter combinations in certain situations, and I have noticed something similar in at least one case ("bryȝt" becoming "bird.")
I have noticed that certain words for somereason my mind has begun switching, such as "thirty [ˈθʌ̆ɻ.ti]" switching to: [ˈθɾɪx.ti] or [ˈθɾiç.ti]. Also "thirteen [θʌ˞ɹʔˈtin]" becoming [ˈθɾɪxtin].
In speech I don't say this, as usually the difference trips me up and I slow down, and say the right word. Just something interesting, I am curious if there are any other similar cases in history. The only thing I can think of that would be comparable would be how some English dialects insert a rhotic consonant where there is naught: America said as: [ˈʌmeɹɪ̈kʊɻ] in some UK dialects, or [hɔɻk] for "hawk."