Identify specific numeric values in a cell such as "1" without counting "11" as two "1"s

I have a spreadsheet that is looking at individual cells and counting specific values that have been entered in them. For example: Cell G2 has 1,1,3,11,7,1 entered in it. I need another cell to count only the "1"s. However, it views 11 as two 1s as well so my result shows 5 when it should be 3. Here is my formula I'm using.

=SUM(LEN(G2)-LEN(SUBSTITUTE(G2,"1","")))/LEN("1")

Tried it and it works if 11 is the only extra item with the number I'm looking for but I still have the same issue of it counting the extra 1s if there are numbers like 13,15,21, etc. The column with multiple numbers are reviews from auditors that are watching for errors. In rare cases, the same error can be made twice so I have to capture that. So I need this to isolate individual numbers. Same issue would happen with any single digit as it shows up again, like 2 will be in 12, all 20s, 32. I appreciate the effort on that try though. thank you so much.

Here is a test copy of the worksheet with items not important to this question stripped down. I'm very new to these forums so please forgive any ignorance on my part. I've included some explanation and details directly on the worksheet.

See if this works for you:

=(LEN(SUBSTITUTE(","&G2&",",",",",,"))-LEN(SUBSTITUTE(SUBSTITUTE(","&G2&",",",",",,"),",1,",",,")))/LEN("1")

I'm about to leave the office for the day but I plugged this in and off of first glance and a few quick tests, it seems to do the trick. I will try more when I'm back in on Tuesday. However, so far, so good. THANK YOU SO MUCH!

This actually seems to work the best. I was running into issues when the previous code got into the errors that had double digits but by replacing the A2 reference with the actual cell containing error findings, then replacing B2 with the target cell, it seems to work like a charm. Thank you so much for the assistance.