@SUM not working

DebraP  I feel your pain. I began using Lotus123 in the 80's and have always used the @ symbol in excel (and I am somewhat of a master at excel, so no dummy). the @ symbol stopped working for me around a week ago, after another company installation of cloud based Thompson Reuters app, requiring 2FA and update to my MS account. Not only can I not use @, my CTRL/spacebar  no longer highlights sections of data before encountering a blank row/column. There are a few other oddities that have not worked but they have been hit and miss and depends on which workbook I am in. It is sooooo frustrating. I cannot type =sum or anyother =formula, my fingers do not work that way!!! No one out there seems to notice as we are too old I guess and very few of us operate this way with @. Its my left hand that moves to hit @ as I'm whizzing thru typing, I cannot make my right hand find =. If I have to retrain my hands I am going to be VERY VERY UNHAPPY! and this still doesnt solve the CTRL/spacebar issue. Turning on the Lotus123 transition box has to be done for each different workbook. Oh how I am not going to do this. It has not been an issue for 40 years, why now??? Hope someone can come up with something or at least a reason why this just started occuring.