Why, when counting the Omer some say Baomer

בעומר / לעומר Why, when counting the Omer some say Baomer    and others say Laomer, and when mentioning   the holiday of Lag Baomer almost all say Lag Baomer and not Lag Laomer?   Perhaps we can say, The ט"ז (O. Ch. 489 sk 3) writes that the ר"ן (end of Pesachim) uses the girsa of Laomer. The ט"ז claims Baomer is more accurate according to Dikduk. Minhag Ashkenaz and the Gra hold to say Baomer. The Arizal -Shlah hold to say Laomer. The Mishna Verura writes that most Poskim hold to say Laomer. The machlokes of Baomer /Laomer is only when performing the mitzvah of Sefira. We find many times Chazal were מתקן Brochos & Tefilos that are not 100% accurate according to Dikduk. For some unknown reason, Chazal decided to use the not so accurate word. eg: instead of לשבת בסוכה (LOSHEVES) we say לישב בסוכה. When no mitzvah is being performed,(in common language) all will agree to use the more accurate word.  (according to Dikduk)  אמבצי