Here is to fix stock valuation layer to current stock.
Issues what this will be fixing:

• Stock Valuation layer doesn't match to qty in stok
• AVCO and FIFO standard price calculations.

These issues might be because something is went wrong in configuration or stock.move's. Like bug in external module. 

These will happen, and I don't know why theres no fix tool built in odoo. 
Or I haven't found it.

 def action_fix_category_svl(self):        
	​self.ensure_one()
   if self.property_cost_method != 'standard':            
	​	​​raise ValidationError(_('You must change valuation type to standard to run this method'))
	​
   products = self.env['product.product'].search([('categ_id', '=', self.id)])               
	​for product in products:                        
	​	​#1. Getting Stock Valuation Layer value and quantity            
	​	​valuation_quantity = product.quantity_svl            
	​	​valuation_value =  product.value_svl            
	​	​#2. Getting in stock value and quantity            
	​	​qty_available = product.qty_available            
	​	​qty_value = product.standard_price * qty_available            
        company_id = self.env.company.id            
	​	​#3. Finding all the stock layers that has remaining qty and remaining value and setting it to zero            
	​	​#This is for avco and fifo calculations. When setting those 0 they are not effecting in standard price            
	​	​#Caluculations             
	​	​domain =  [
	​	​	​('product_id', '=', product.id),                
	​	​	​('company_id', '=', company_id),                
	​	​	​('remaining_qty', '!=', 0)
	​	​]            
	​	​svls = self.env['stock.valuation.layer'].search(domain)
       	​for svl in svls:               
	​	​	​svl.write({"remaining_qty": 0})
	​	​
       domain = [                
	​	​	​('product_id', '=', product.id),
            ('company_id', '=', company_id),                
	​	​	​('remaining_value', '!=', 0)            
	​	​]            
	​	​svls = self.env['stock.valuation.layer'].search(domain)           
       	​for svl in svls:               
	​	​	​svl.write({"remaining_value": 0})
          
       	​#5. Calculating real stock adjustment for stock valuation layer            
	​	​#This method makes adjustment for example adjustment to 20 from -20 would be 40            
	​	​qty_to_svl = self.fix_value(qty_available, valuation_quantity)            
	​	​value_to_svl = self.fix_value(qty_value, valuation_value)
       	​vals = {
	​	​	​'product_id': product.id,                
	​	​	​'value': value_to_svl,                
	​	​	​'unit_cost': 0,                
	​	​	​'quantity': qty_to_svl,                
	​	​	​'remaining_qty': 0,                
	​	​	​'remaining_value':0,                
	​	​	​'company_id': self.env.company.id,                
	​	​	​'description': _('Fixing of %s to match stock.quant valuation %s with qty %s', product.name,  qty_value, qty_available)                          	​	​}            
	​	​self.env['stock.valuation.layer'].sudo().create(vals)