Detect the Nearly Perfect Licence Plates Note: This is inspired by this question by @Willbeing where task was to count the number of perfect plates of a certain length, but it's slightly different.

We call a perfect licence plate that plate whose text satisfies the following conditions:

It consists of characters, which can either be uppercase letters([A-Z]) or digits([0-9])
Summing the positions of its letters in the English alphabet, 1-indexed (i.e: A=1,B=2,...,Z=26) gives an integer n
Getting each chunk of digits, summing them and then multiplying all the results gives the same result, n
n is a perfect square (e.g: 49 (72), 16 (42))

A nearly perfect licence plate meets the conditions for a perfect licence plate, except that n is not a perfect square.

Input
A string representing the text of the licence plate, taken as input in any standard form, except for hardcoding.
Output
If the given string represents a nearly perfect licence plate, return a truthy value (e.g: True / 1), otherwise return a falsy value (e.g: False / 0). Any standard form of output is accepted while taking note that this loopholes are strictly forbidden.

Examples
licence plate -&gt; output


A1B2C3 -&gt; 1

A + B + C = 1 + 2 + 3 = 6
1 * 2 * 3 = 6 
6 is not a perfect square, 6 = 6 =&gt; nearly perfect plate

01G61 -&gt; 1

(0 + 1) * (6 + 1) = 7
G = 7
7 is not a perfect square, 7 = 7 =&gt; nearly perfect plate

11BB2 -&gt; 0

(1 + 1) * 2 = 4
B + B = 2 + 2 = 4
4 = 4, but 4 is the square of 2 =&gt; perfect license plate (not what we want)

67FF1 -&gt; 0

(6 + 7) * 1 = 13
F + F = 6 + 6 = 12
12 != 13 =&gt; not perfect at all!


Scoring
This is code-golf, so the shortest answer in bytes wins!
Jelly, 29 28 30 bytes
+1 byte to fix a bug spotted by ChristianSievers (incorrectly dealing with substrings of only zeros)
+1 byte to fix false positives for &quot;0&quot;, &quot;00&quot;, ... found during above fixing (0 is a perfect square).
i@€ØAS;Æ²$
e€ØAœpV€€LÐfS€P;0⁼Ç

Try it online!, or run tests
How?
i@€ØAS;Æ²$ - Link 1: [letter-sum, letter-sum is perfect square?]: plate
i@€        - index of €ach char in plate [reversed @rguments] (1-based, 0 otherwise) in:
   ØA      -     uppercase alphabet
     S     - sum
         $ - last two links as a monad:
      ;    -     concatenate with:
       Æ²  -         is square?

e€ØAœpV€€LÐfS€P;0⁼Ç - Main link: plate                        e.g. &quot;11BB2&quot;
    œp              - partition plate at truthy values of:
e€                  -     is in? for €ach char in plate:
  ØA                -         uppercase alphabet                   [['1','1'],[''],['2']]
      V€€           - evaluate for €ach for €ach                   [[1,1],[],[2]]
          Ðf        - filter keep:
         L          -     length                                   [[1,1],[2]]
            S€      - sum each                                     [2,2]
              P     - product                                      4
               ;0   - concatenate a zero                           [4,0]
                  Ç - last link (1) as a monad (taking plate)      [4,1]
                 ⁼  - equal? (non-vectorising)                     0